tag:blogger.com,1999:blog-55218627521634727522024-03-15T07:27:43.112-07:00ELECTRICAL OBJECTIVE QUESTIONS WITH ANSWERSFor Electrical and Electronics Engineers who are preparing for Technical Interviews, Competitive Exams, Entrance Exams... You can find solved objective type questions for Power Electronics, Digital Electronics, Electrical machines, Power systems, basic electrical and electronics, measurements & Instrumentation etc.adminhttp://www.blogger.com/profile/03959820607389481053noreply@blogger.comBlogger94125tag:blogger.com,1999:blog-5521862752163472752.post-78565477298219594162017-08-12T00:08:00.002-07:002017-08-14T08:58:01.255-07:00Electronic Devices Objective Type Questions with Answers: Part-7<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="font-size: small;"><u>Electronic Devices Objective MCQ Questions with Answers: Part-7</u></span></h2>
<span style="color: red;">(1) The reverse current in a diode is of the order of</span><br />
<b>Options:</b><br />
[a] kA<br />
[b] mA<br />
[c] μA<br />
[d] A<br />
<b>Answers:</b><br />
1. Options B and C<br />
2. Option C only<br />
3. Option D only<br />
4. Option A and D only<br />
<div id="spoiler1" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 2 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">(2) The forward voltage drop across a diode is about....</span><br />
[a] 2.5V<br />
[b] 3V<br />
[c] 10V<br />
[d] 0.7V<br />
<div id="spoiler2" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">(3) A semiconductor diode is used as</span><br />
<b>Options:</b><br />
[a] An amplifier<br />
[b] A Rectifier<br />
[c] An oscillator<br />
[d] A voltage regulator<br />
<b>Answers:</b><br />
1. Options A and C<br />
2. Option B only<br />
3. A, B, C and D<br />
4. Option D only<br />
<div id="spoiler3" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 2 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">(4) A semiconductor diode has ....</span><br />
[a] One PN junction<br />
[b] Two PN junction<br />
[c] Three PN junction<br />
[d] Four PN junction<br />
<div id="spoiler4" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">(5) A semiconductor diode has forward resistance of order of</span><br />
<b>Options:</b><br />
[a] k Ω<br />
[b] Ω<br />
[c] M Ω<br />
[d] μΩ<br />
<b>Answers:</b><br />
1. Option D only<br />
2. Option B only<br />
3. Options A, B, C and D<br />
4. None of the above<br />
<div id="spoiler5" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 2 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<div>
<br /></div>
<div>
<span style="color: red;">(6) If the arrow of diode symbol is positive with respect to bar, then the diode is .... biased</span><br />
[a] Forward<br />
[b] Reverse<br />
[c] Either forward or reverse<br />
[d] None of the above<br />
<div id="spoiler6" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;"><br /></span>
<span style="color: red;">(7) The leakage current in a diode is due to</span><br />
<b>Options:</b><br />
[a] Minority Carriers<br />
[b] Majority Carriers<br />
[c] Junction Capacitance<br />
[d] None of the above<br />
<b>Answers:</b><br />
1. Options A, B, C<br />
2. Option B only<br />
3. Options A and B only<br />
4. Option A only<br />
<div id="spoiler7" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 4 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<div>
<br /></div>
<span style="color: red;">(8) The DC resistance of a diode is ..... its AC resistance</span><br />
[a] Same as<br />
[b] More than<br />
[c] Less than<br />
[d] None of the above<br />
<div id="spoiler8" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;"><br /></span>
<span style="color: red;">(9) An ideal diode is one which behaves as a perfect .... when forward biased</span><br />
[a] Conductor<br />
[b] Insulator<br />
[c] Resistance material<br />
[d] None of the above</div>
<div id="spoiler9" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<div>
<span style="color: red;"><br /></span></div>
<div>
<span style="color: red;">(10) If the temperature of the diode increases,then leakage current....</span><br />
[a] Remains same<br />
[b] Decreases<br />
[c] Increases<br />
[d] Becomes zero<br />
<div id="spoiler10" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
Please leave your comments below.... Please subscribe to get new posts to your mail ID.....</div>
</div>
Anonymoushttp://www.blogger.com/profile/04540939319476033259noreply@blogger.com4tag:blogger.com,1999:blog-5521862752163472752.post-41206147659067100602016-11-28T02:10:00.000-08:002016-11-28T02:10:02.608-08:00Multiple Choice Questions with Answers on Thyristors (SCR)<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="color: #38761d; font-size: small;">Multiple Choice Questions Answers on Thyristors (SCR)</span></h2>
<span style="color: red;">1. An SCR is a ...... triggered device</span><br />
(1) Voltage<br />
(2) Current<br />
(3) Voltage as well as current<br />
(4) None of the above<br />
<div id="spoiler1" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 2 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">2. In an SCR circuit, the supply voltage is generally ......... that of breakover voltage</span><br />
(1) Equal to<br />
(2) Less than<br />
(3) Greater than<br />
(4) None of the above<br />
<div id="spoiler2" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 2 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">3. When an SCR is turned on, the voltage across it is about ..........</span><br />
(1) zero<br />
(2) 10 V<br />
(3) 0.1 V<br />
(4) 1V<br />
<div id="spoiler3" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 4 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">4. An SCR is turned off when</span><br />
(1) Anode current is reduced to zero<br />
(2) Gate voltage is reduced to zero<br />
(3) Gate is reverse biased<br />
(4) None of the above<br />
<div id="spoiler4" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 1 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;"><br /></span>
<span style="color: red;">5. In an SCR circuit, the angle of conduction can be changed by</span><br />
(1) Changing anode voltage<br />
(2) Changing gate voltage<br />
(3) Reverse biasing the gate<br />
(4) None of the above<br />
<div id="spoiler5" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 2 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">6. If firing angle is increased, then the output of an SCR</span><br />
(1) Remains the same<br />
(2) Is increased<br />
(3) Is decreased<br />
(4) None of the above<br />
<div id="spoiler6" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:3 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">7. If gate current is increased, then anode-cathode voltage at which SCR turns ON</span><br />
(1) is decreased<br />
(2) is increased<br />
(3) remains the same<br />
(4) none of the above<br />
<div id="spoiler7" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 1 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">8. An SCR has ........... PN junctions.</span><br />
(1) Two<br />
(2) Three<br />
(3) Four<br />
(4) None of the above<br />
<div id="spoiler8" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 2 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">9. An SCR has ........ semiconductor layers.</span><br />
(1) Two<br />
(2) Three<br />
(3) Four<br />
(4) None of the above<br />
<div id="spoiler9" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 3 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">10. In AC supply, an SCR can exercise control over</span><br />
(1) Positive half-cycles only<br />
(2) Negative half-cycles only<br />
(3) Both positive and negative half-cycles<br />
(4) Positive or negative half-cycles<br />
<div id="spoiler10" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 4 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">11. AC power in a load can be controlled by connecting</span><br />
(1) Two SCRs in series<br />
(2) Two SCRs in parallel<br />
(3) Two SCRs in parallel opposition<br />
(4) None of the above<br />
<div id="spoiler11" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 3 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler11') .style.display=='none')
{document.getElementById('spoiler11') .style.display=''}
else{document.getElementById('spoiler11') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">12. When SCR starts conducting, which loses all control?</span><br />
(1) Cathode<br />
(2) Gate<br />
(3) Anode<br />
(4) None of the above<br />
<div id="spoiler12" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 2 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler12') .style.display=='none')
{document.getElementById('spoiler12') .style.display=''}
else{document.getElementById('spoiler12') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br /></div>
Anonymoushttp://www.blogger.com/profile/04540939319476033259noreply@blogger.com2tag:blogger.com,1999:blog-5521862752163472752.post-59501284369456194252016-11-26T01:05:00.000-08:002016-11-26T01:28:16.717-08:00Thyristor(SCR) Objective Type Questions with Answers<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="color: #38761d; font-size: small;"><u>Power Electronics Objective Type Questions with Answers on SCR</u></span></h2>
<span style="color: red;">1. An SCR is made of silicon and not germanium because silicon ....</span><br />
(1) is inexpensive<br />
(2) is mechanically strong<br />
(3) has small leakage current<br />
(4) is tetravalent<br />
<div id="spoiler1" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 3 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">2. An SCR is a solid state equivalent of ...</span><br />
(1) Triode<br />
(2) Pentode<br />
(3) Gas-filled triode<br />
(4) Tetrode<br />
<div id="spoiler2" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 3 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">3. An SCR behaves as a ............... switch</span><br />
(1) Unidirectional<br />
(2) Bidirectional<br />
(3) Mechanical<br />
(4) None of the above<br />
<div id="spoiler3" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:1 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;"><br /></span>
<span style="color: red;">4. An SCR has three terminals viz. ...</span><br />
(1) cathode, anode, gate<br />
(2) anode, cathode, grid<br />
(3) anode, cathode, drain<br />
(4) none of the above<br />
<div id="spoiler4" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 1 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">5. An SCR is made of</span><br />
(1) Germanium<br />
(2) Silicon<br />
(3) Carbon<br />
(4) None of the above<br />
<br />
(a) 1 only<br />
(b) 2 only<br />
(c) 1 & 2 only<br />
(d) 1,2,3 only<br />
<div id="spoiler5" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: b </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">6. An SCR is also known as</span><br />
(1) Triac<br />
(2) Diac<br />
(3) Unijunction transistor<br />
(4) Thyristor<br />
<div id="spoiler6" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:4 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;"><br /></span>
<span style="color: red;">7. In the normal operation of an SCR, anode is ........ with respect to cathode</span><br />
(1) at zero potential<br />
(2) negative<br />
(3) positive<br />
(4) none of the above<br />
<div id="spoiler7" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 3 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;"><br /></span>
<span style="color: red;">8. An SCR combines the features of ........</span><br />
(1) a rectifier and resistance<br />
(2) a rectifier and transistor<br />
(3) a rectifier and capacitor<br />
(4) none of the above<br />
<div id="spoiler8" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 2 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">9. In normal operation of an SCR, gate is .......... with respect to cathode</span><br />
(1) positive<br />
(2) negative<br />
(3) at zero potential<br />
(4) none of the above<br />
<div id="spoiler9" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 1 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">10. When SCR is OFF, the current in the circuit is .........</span><br />
(1) exactly zero<br />
(2) small leakage current<br />
(3) large leakage current<br />
(4) none of the above<br />
<div id="spoiler10" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 2 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">11. The control element in an SCR is .......</span><br />
(1) cathode<br />
(2) anode<br />
(3) anode supply<br />
(4) gate<br />
<div id="spoiler11" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:4 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler11') .style.display=='none')
{document.getElementById('spoiler11') .style.display=''}
else{document.getElementById('spoiler11') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">12. The normal way to turn on an SCR is by.......</span><br />
(1) Breakover voltage<br />
(2) Appropriate anode current<br />
(3) Appropriate gate current<br />
(4) None of the above<br />
<div id="spoiler12" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 3 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler12') .style.display=='none')
{document.getElementById('spoiler12') .style.display=''}
else{document.getElementById('spoiler12') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">13. An SCR is turned off by ........</span><br />
(1) Reducing anode voltage to zero<br />
(2) Reducing gate voltage to zero<br />
(3) Reverse biasing the gate<br />
(4) None of the above<br />
<div id="spoiler13" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 1 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler13') .style.display=='none')
{document.getElementById('spoiler13') .style.display=''}
else{document.getElementById('spoiler13') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> </div>
Anonymoushttp://www.blogger.com/profile/04540939319476033259noreply@blogger.com0tag:blogger.com,1999:blog-5521862752163472752.post-59108894259317153952016-06-06T01:18:00.000-07:002016-11-26T01:48:24.784-08:00Measurements Instrumentation MCQ Questions Answers: Part-11<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<div style="line-height: 24px;">
<h2 style="text-align: left;">
<span style="color: #38761d; font-family: Georgia, Times New Roman, serif; font-size: small;"><u>Measurements Instrumentation MCQ Questions Answers: Part-11</u></span></h2>
<div style="font-family: georgia, "times new roman", "bitstream charter", times, serif; font-size: 16px;">
<span style="color: red;">[1] The percentage limiting error, in the case of an instrument reading of 8.3V with a 0 to 150V voltmeter having a guaranteed accuracy of 1% full-scale reading is </span></div>
</div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
A) 1.810%<br />
B) 0.181%<br />
C) 0.0018%<br />
D) 18.10%</div>
<div id="spoiler1" style="display: none;">
<span data-mce-style="color: #ff0000;" style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans:D </b></span>
</span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span>
</span>
<br />
<div style="font-family: georgia, 'times new roman', 'bitstream charter', times, serif; font-size: 16px; line-height: 24px;">
<div style="color: #333333;">
<br /></div>
<span style="color: red;">[2] The induction of a high Q inductor can be measured by a </span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
A) Schering Bridge<br />
B) Hay Bridge<br />
C) Maxwell Bridge<br />
D) Wien Bridge</div>
<div id="spoiler2" style="display: none;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span>
</span></span>
<br />
<div style="font-family: georgia, 'times new roman', 'bitstream charter', times, serif; font-size: 16px; line-height: 24px;">
<div style="color: #333333;">
<br /></div>
<span style="color: red;">[3] If a DC voltmeter is made from an ammeter having a fed of 100μA then its sensitivity (in KΩ/V) will be</span></div>
<div style="font-family: georgia, 'times new roman', 'bitstream charter', times, serif; font-size: 16px; line-height: 24px;">
A) 1<br />
<div style="color: #333333;">
B) 100</div>
<div style="color: #333333;">
C) 10</div>
<div style="color: #333333;">
D) 1000</div>
</div>
<div id="spoiler3" style="display: none;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans:C</b></span>
</span></span></span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span></span>
</span></span><br />
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><br /></span></span>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">Guidelines: Assertion (A) and Reason (R) type Questions 4 and 5:</span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">
</span></span>
<br />
<div style="font-family: georgia, 'times new roman', 'bitstream charter', times, serif; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">(A) Both a and R are correct and R is explanation for A.</span></span><br />
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">(B) Both a and R are correct and R is not explanation for A.</span></span><br />
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">(C) A is true but R is false.</span></span><br />
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">(D) A is false but R is true.</span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">
</span></span>
<br />
<div style="font-family: georgia, 'times new roman', 'bitstream charter', times, serif; font-size: 16px; line-height: 24px;">
<div style="color: #333333;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><br /></span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">[4] A: The screen of a CRT is coated with phosphor on the inside.</span></span><br />
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"> R: Phosphor absorbs the KE of the bombarding electrons and re-emits energy at a frequency in the visible region.</span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">
</span></span>
<br />
<div id="spoiler4" style="display: none;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans:A </b></span>
</span></span></span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span>
</span></span></span><br />
<div style="font-size: 16px; line-height: 24px;">
<div style="color: #333333;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span style="color: red; font-family: Georgia, Times New Roman, serif;"><br /></span></span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span style="color: red; font-family: Georgia, Times New Roman, serif;">[5] A: The Weign Bridge can be used for frequency measurements.</span></span></span><br />
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span style="color: red; font-family: Georgia, Times New Roman, serif;"> B: The Weign Bridge uses only capacitors and resistors.</span></span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;">
<div id="spoiler5" style="display: none;">
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans:A </b></span>
</span></span></div>
<div id="spoiler5" style="display: none;">
</div>
</span></span></span></div>
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
</span>
<br />
<div style="font-family: georgia, 'times new roman', 'bitstream charter', times, serif; font-size: 16px; line-height: 24px;">
<div style="color: #333333;">
<br /></div>
<span style="color: red;">[6] It is desired to convert a 0-1000A meter movement, with an internal resistance of 100 ohms, into a 0-100mA meter. The required value of shunt resistance is about</span></div>
<div style="font-family: georgia, 'times new roman', 'bitstream charter', times, serif; font-size: 16px; line-height: 24px;">
A) 0.1 ohms<br />
<div style="color: #333333;">
B) 1 ohms</div>
<div style="color: #333333;">
C) 99 ohms</div>
<div style="color: #333333;">
D) 100 ohms</div>
</div>
<div id="spoiler6" style="display: none;">
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></span></div>
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span>
</span><br />
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><br /></span>
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;">[7] Match List I with List II:</span></div>
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;">
<table class="mce-item-table" style="border: 1px dashed rgb(187, 187, 187); color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px; width: 676px;"><tbody>
<tr><td style="border: 1px dashed rgb(187, 187, 187); font-family: inherit; font-size: inherit;"> List I</td><td style="border: 1px dashed rgb(187, 187, 187); font-family: inherit; font-size: inherit;"> List II</td></tr>
<tr><td style="border: 1px dashed rgb(187, 187, 187); font-family: inherit; font-size: inherit;">(a) Megger</td><td style="border: 1px dashed rgb(187, 187, 187); font-family: inherit; font-size: inherit;">(p) Measurement of loss angle in a dielectric</td></tr>
<tr><td style="border: 1px dashed rgb(187, 187, 187); font-family: inherit; font-size: inherit;">(b) Spectrum analyzer</td><td style="border: 1px dashed rgb(187, 187, 187); font-family: inherit; font-size: inherit;">(q) Measurement of frequency</td></tr>
<tr><td style="border: 1px dashed rgb(187, 187, 187); font-family: inherit; font-size: inherit;">(c) Schering bridge</td><td style="border: 1px dashed rgb(187, 187, 187); font-family: inherit; font-size: inherit;">(r) Measurement of insulation resistance</td></tr>
<tr><td style="border: 1px dashed rgb(187, 187, 187); font-family: inherit; font-size: inherit;">(d) Digital counter</td><td style="border: 1px dashed rgb(187, 187, 187); font-family: inherit; font-size: inherit;">(s) Measurement of harmonics</td></tr>
</tbody></table>
</span><br />
<div id="spoiler7" style="display: none;">
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: a-r, b-a, c-p, d-q </b></span>
</span></span></span></span></div>
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;">
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;">
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span>
</span></span></span><br />
<div style="font-size: 16px; line-height: 24px;">
<div style="color: #333333; font-family: georgia, "times new roman", "bitstream charter", times, serif;">
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><br /></span></span></span></div>
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: Georgia, Times New Roman, serif;">[8] In moving coil meters, damping is provided by</span></span></span></div>
<span style="font-family: Georgia, Times New Roman, serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;">
</span></span></span>
</span><br />
<div style="font-size: 16px; line-height: 24px;">
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: Georgia, Times New Roman, serif;">A) damping vane in the air tight chamber.</span></span></span><br />
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: Georgia, Times New Roman, serif;">B) the aluminium frame of the coil.</span></span></span><br />
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: Georgia, Times New Roman, serif;">C) eddy current disk.</span></span></span><br />
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: Georgia, Times New Roman, serif;">D) The coil spring attached to the moving mechanism.</span></span></span></div>
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;">
</span></span></span>
<div id="spoiler8" style="display: none;">
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></span></span></span></span></span></span></div>
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;">
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"> <span style="color: red; text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<div style="color: red; font-family: georgia, 'times new roman', 'bitstream charter', times, serif; font-size: 16px; line-height: 24px;">
<div style="color: #333333;">
<br /></div>
[9] A 0 to 300V voltmeter has a guaranteed accuracy of 1% of full scale reading. The voltage measured by the instrument is 83V. The percentage limiting error is </div>
<div style="font-family: georgia, 'times new roman', 'bitstream charter', times, serif; font-size: 16px; line-height: 24px;">
A) 95%<br />
<div style="color: #333333;">
B) 4.85%</div>
<div style="color: #333333;">
C) 3.62%</div>
<div style="color: #333333;">
D)1.81%</div>
</div>
<div id="spoiler9" style="display: none;">
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></span></div>
</span></span></span>
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;">
<span style="font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span>
<div style="font-family: georgia, 'times new roman', 'bitstream charter', times, serif; font-size: 16px; line-height: 24px;">
<div style="color: #333333;">
<br /></div>
[10] An Aryton shunt is used to make a D'Arsonval galvanometer into a<br />
<div style="color: #333333;">
A) single range voltmeter</div>
<div style="color: #333333;">
B) single range ammeter</div>
<div style="color: #333333;">
C) multi range ammeter</div>
<div style="color: #333333;">
D) multi range voltmeter</div>
</div>
<div id="spoiler10" style="display: none;">
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></span></span></span></span></span></div>
<span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red; font-family: "arial" , "helvetica" , sans-serif;">
<span style="font-family: "arial" , "helvetica" , sans-serif;"><span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span>
<div class="mce-resize-bar mce-resize-bar-row" data-mce-bogus="all" data-mce-resize="false" data-mce-style="cursor: row-resize; margin: 0; padding: 0; position: absolute; left: 10px; top: 1321px; height: 4px; width: 676px; " data-row="0" style="color: #333333; cursor: row-resize; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; height: 4px; left: 10px; line-height: 24px; margin: 0px; padding: 0px; position: absolute; top: 1321px; width: 676px;" unselectable="on">
</div>
<div class="mce-resize-bar mce-resize-bar-row" data-mce-bogus="all" data-mce-resize="false" data-mce-style="cursor: row-resize; margin: 0; padding: 0; position: absolute; left: 10px; top: 1351px; height: 4px; width: 676px; " data-row="1" style="color: #333333; cursor: row-resize; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; height: 4px; left: 10px; line-height: 24px; margin: 0px; padding: 0px; position: absolute; top: 1351px; width: 676px;" unselectable="on">
</div>
<div class="mce-resize-bar mce-resize-bar-row" data-mce-bogus="all" data-mce-resize="false" data-mce-style="cursor: row-resize; margin: 0; padding: 0; position: absolute; left: 10px; top: 1381px; height: 4px; width: 676px; " data-row="2" style="color: #333333; cursor: row-resize; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; height: 4px; left: 10px; line-height: 24px; margin: 0px; padding: 0px; position: absolute; top: 1381px; width: 676px;" unselectable="on">
</div>
<div class="mce-resize-bar mce-resize-bar-row" data-mce-bogus="all" data-mce-resize="false" data-mce-style="cursor: row-resize; margin: 0; padding: 0; position: absolute; left: 10px; top: 1411px; height: 4px; width: 676px; " data-row="3" style="color: #333333; cursor: row-resize; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; height: 4px; left: 10px; line-height: 24px; margin: 0px; padding: 0px; position: absolute; top: 1411px; width: 676px;" unselectable="on">
</div>
<div class="mce-resize-bar mce-resize-bar-row" data-mce-bogus="all" data-mce-resize="false" data-mce-style="cursor: row-resize; margin: 0; padding: 0; position: absolute; left: 10px; top: 1439px; height: 4px; width: 676px; " data-row="4" style="color: #333333; cursor: row-resize; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; height: 4px; left: 10px; line-height: 24px; margin: 0px; padding: 0px; position: absolute; top: 1439px; width: 676px;" unselectable="on">
</div>
<div class="mce-resize-bar mce-resize-bar-col" data-col="0" data-mce-bogus="all" data-mce-resize="false" data-mce-style="cursor: col-resize; margin: 0; padding: 0; position: absolute; left: 240px; top: 1290px; height: 154px; width: 4px; " style="color: #333333; cursor: col-resize; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; height: 154px; left: 240px; line-height: 24px; margin: 0px; padding: 0px; position: absolute; top: 1290px; width: 4px;" unselectable="on">
</div>
</span></span></span></span></span></span></span></span></div>
Anonymoushttp://www.blogger.com/profile/04540939319476033259noreply@blogger.com8tag:blogger.com,1999:blog-5521862752163472752.post-79251996033339306382016-04-30T01:57:00.001-07:002016-04-30T01:57:11.141-07:00Measurements Instrumentation Objective Type Questions Answers: Part-10<div dir="ltr" style="text-align: left;" trbidi="on">
<div style="line-height: 24px;">
<h2 style="text-align: left;">
<span data-mce-style="color: #ff0000;" style="color: #38761d; font-family: inherit; font-size: small;"><u>Measurements Instrumentation Objective Type Questions Answers: Part-10</u></span></h2>
<div style="color: #333333; font-size: 16px;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">[1] A 12 bit counter type A/D converter uses a 1 MHz clock. Its maximum conversion time is</span></div>
<div style="color: #333333; font-size: 16px;">
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">A) 1 μs</span></div>
<div style="color: #333333; font-size: 16px;">
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">B) 12μs</span></div>
<div style="color: #333333; font-size: 16px;">
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">C) 4096μs</span></div>
<div style="color: #333333; font-size: 16px;">
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">D) 4μs</span></div>
</div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #008000;" style="color: green; font-family: inherit;"><strong></strong></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">
</span><br />
<div id="spoiler1" style="display: none;">
<span data-mce-style="color: #ff0000;" style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans:C </b></span>
</span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br /><span style="font-family: inherit;">[2] A 12 bit counter type A/D converter uses a 1 MHz clock. Its maximum conversion rate is</span></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">A) 10<sup data-mce-bogus="1">6</sup> conversions/sec</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">B) 244 conversions/sec</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">C) 488 conversions/sec</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">D) 83 kilo conversions/sec</span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #008000;" style="color: green; font-family: inherit;"><strong></strong></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">
</span><br />
<div id="spoiler2" style="display: none;">
<span data-mce-style="color: #ff0000;" style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br /><span style="font-family: inherit;">[3] An 8 bit converter type A/D converter makes at least 8000conversions/sec. The clock frequency used is</span></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
</div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">A) 2MHz</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">B) 8MHz</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">C) 1MHz</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">D) 4MHz</span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">
</span><br />
<div id="spoiler3" style="display: none;">
<span data-mce-style="color: #ff0000;" style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br /><span style="font-family: inherit;">[4] The conversion time of a 12 bit successive approximation A/D converter using a 1 MHz clock is </span></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
</div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">A) 1 μs</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">B) 12μs</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">C) 4096μs</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">D) 4095μs</span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #008000;" style="color: green; font-family: inherit;"><strong></strong></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">
</span><br />
<div id="spoiler4" style="display: none;">
<span data-mce-style="color: #ff0000;" style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br /><span style="font-family: inherit;">[5] The resolution of a 12 bit D/A converter using a binary ladder is </span></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
</div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">A) 4096</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">B) 0.02%</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">C) 2.4%</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">D) 4%</span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #008000;" style="color: green; font-family: inherit;"><strong></strong></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">
</span><br />
<div id="spoiler5" style="display: none;">
<span data-mce-style="color: #ff0000;" style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br /><span style="font-family: inherit;">[6] A 12 bit counter type A/D converter uses a 1 MHz clock. If the full scale output is +10V, its resolution output is</span></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
</div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">A) 2.44mV</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">B) 2.4mV</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">C) 0.02V</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">D) 0.02mV</span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #008000;" style="color: green; font-family: inherit;"><strong></strong></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">
</span><br />
<div id="spoiler6" style="display: none;">
<span data-mce-style="color: #ff0000;" style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br /><span style="font-family: inherit;">[7] A 10 bit resistive divider is constructed such that the current through the LSB resistor is 100μA. The maximum current that will flow through the MSB resistor is </span></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
</div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">A) 200μA.</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">B) 1mA</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">C) 51.2mA </span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">D) 102.4mA</span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #008000;" style="color: green; font-family: inherit;"><strong></strong></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">
</span><br />
<div id="spoiler7" style="display: none;">
<span data-mce-style="color: #ff0000;" style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans:C </b></span>
</span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br /><span style="font-family: inherit;">[8] For a certain 4 bit successive approximation A/D converter, the maximum ladder output is +8V. if a constant +6V is applied to the analog input the sequence of binary states for the SA register is </span></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
</div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">A) 1111</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">B) 1010</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">C) 0110</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">D) 1011</span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #008000;" style="color: green; font-family: inherit;"><strong></strong></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">
</span><br />
<div id="spoiler8" style="display: none;">
<span data-mce-style="color: #ff0000;" style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br /><span style="font-family: inherit;">[9] In the case of power measurement by two wattmeter method in a balanced 3Φ system with a pure inductive load </span></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
</div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">A) both the Wattmeter will indicate the same but of opposite sign.</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">B) both the Wattmeters will indicate zero.</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">C) both the Wattmeters will indicate same value and of the same sign.</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">D) one Wattmeter will indicate zero and the other non-zero value.</span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #008000;" style="color: green; font-family: inherit;"><strong></strong></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;">
</span><br />
<div id="spoiler9" style="display: none;">
<span data-mce-style="color: #ff0000;" style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red; font-family: inherit;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br /><span style="font-family: inherit;">[10] The sensitivity of an instrument is </span></span></div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
</div>
<div style="color: #333333; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">A) smallest increment in the output the can be detected with certainity.</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">B) largest input change to which the instrument fails to respond.</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">C) ratio of the change in the magnitude of the output to the corresponding change in the magnitude of the input.</span><br />
<span data-mce-style="color: #000000;" style="color: black; font-family: inherit;">D) closeness of the output values for repeated applications of a constant input.</span></div>
<div style="font-size: 16px; line-height: 24px;">
<div style="color: #333333;">
<span data-mce-style="color: #008000;" style="color: green; font-family: inherit;"><strong></strong></span></div>
<div id="spoiler10" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="font-family: inherit;"><span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> </span><br />
<div style="text-align: left;">
<span data-mce-style="color: #008000;" style="color: green; font-family: inherit;">Thanks for reading...</span></div>
</div>
</div>
Anonymoushttp://www.blogger.com/profile/04540939319476033259noreply@blogger.com9tag:blogger.com,1999:blog-5521862752163472752.post-7686092590534576932016-02-09T07:56:00.000-08:002017-01-07T18:54:59.956-08:00Electrical Engineering Basics Objective Questions with Answers: Part-17<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="color: #274e13; font-size: small;"><u>Electrical Engineering Basics Objective Questions with Answers</u></span></h2>
<span style="color: red;">[1] Electrostatics is a branch of electricity concerned with</span><br />
(a) Energy flowing across a gap between conductors<br />
(b) Charges at rest<br />
(c) Charges in motion<br />
(d) Energy in the form of charges<br />
<div id="spoiler1" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Answer: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[2] Four 2 μF capacitors are connected in series. The equivalent capacitance is</span><br />
(a) 8 μF<br />
(b) 0.5 μF<br />
(c) 2 μF<br />
(d) 6 μF<br />
<div id="spoiler2" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[3] State which of the following is false.</span><br />
The capacitance of a capacitor<br />
(a) Is proportional to the cross-sectional area of the plates<br />
(b) Is proportional to the distance between the plates<br />
(c) Depends on the number of plates<br />
(d) Is proportional to the relative permittivity of the dielectric<br />
<div id="spoiler3" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[4] The capacitance of a capacitor is the ratio</span><br />
(a) Charge to potential difference between plates<br />
(b) Potential difference between plates to plate spacing<br />
(c) Potential difference between plates to thickness of dielectric<br />
(d) Potential difference between plates to charge<br />
<div id="spoiler4" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[5] Which of the following statement is false?</span><br />
(a) An air capacitor is normally a variable type<br />
(b) A paper capacitor generally has a shorter service life than most other types of<br />
capacitor<br />
(c) An electrolytic capacitor must be used only on a.c. supplies<br />
(d) Plastic capacitors generally operate satisfactorily under conditions of high temperature<br />
<div id="spoiler5" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[6] The potential difference</span><span style="color: red;"> across a 10 μF capacitor to charge it with 10mC is</span><br />
(a) 10V<br />
(b) 1 kV<br />
(c) 1V<br />
(d) 10V<br />
<div id="spoiler6" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<div>
<br /></div>
<span style="color: red;">[7] The energy stored in a 10μF capacitor when charged to 500V is</span><br />
(a) 1.25 mJ<br />
(b) 0.025 μJ<br />
(c) 1.25 J<br />
(d) 1.25 C<br />
<div id="spoiler7" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;"><b><br /></b></span>
<span style="color: red;">[8] The capacitance of a variable air capacitor is at maximum when</span><br />
(a) The movable plates half overlap the fixed plates<br />
(b) The movable plates are most widely separated from the fixed plates<br />
(c) Both sets of plates are exactly meshed<br />
(d) The movable plates are closer to one side of the fixed plate than to the other<br />
<div id="spoiler8" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[9] The unit of magnetic flux density is the:</span><br />
(a) Weber<br />
(b) Weber per metre<br />
(c) Ampere per metre<br />
(d) Tesla<br />
<div id="spoiler9" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<div>
<br /></div>
<div>
<span style="color: red;">[10] The charge on a 10 pF capacitor when the voltage applied to it is 10 kV is</span><br />
(a) 100 μC<br />
(b) 0.1 C<br />
(c) 0.1 μC<br />
(d) 0.01 μC<br />
<div id="spoiler10" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[11] Four 2 μF capacitors are connected in parallel. The equivalent capacitance is</span><br />
(a) 8 μF<br />
(b) 0.5 μF<br />
(c) 2 μF<br />
(d) 6 μF<br />
<div id="spoiler11" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler11') .style.display=='none')
{document.getElementById('spoiler11') .style.display=''}
else{document.getElementById('spoiler11') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;"><b><br /></b></span>
<span style="color: red;">[12] In a series a.c. circuit the voltage across a pure inductance is 12V and the voltage across a pure resistance is 5V. The supply voltage is</span><br />
(a) 13V<br />
(b) 17V<br />
(c) 7V<br />
(d) 2.4V<br />
<div id="spoiler12" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler12') .style.display=='none')
{document.getElementById('spoiler12') .style.display=''}
else{document.getElementById('spoiler12') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[13] Inductive reactance results in a current that</span><br />
(a) Leads the voltage by 90deg<br />
(b) Is in phase with the voltage<br />
(c) Leads the voltage by π rad<br />
(d) Lags the voltage by π/2 rad<br />
<div id="spoiler13" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler13') .style.display=='none')
{document.getElementById('spoiler13') .style.display=''}
else{document.getElementById('spoiler13') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[14] A 10Ω resistor is connected in parallel with a 15 Ω resistor and the combination in series with a 12 Ω resistor. The equivalent resistance of the circuit is:</span><br />
(a) 37Ω<br />
(b) 18 Ω<br />
(c) 27 Ω<br />
(d) 4 Ω<br />
<div id="spoiler14" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler14') .style.display=='none')
{document.getElementById('spoiler14') .style.display=''}
else{document.getElementById('spoiler14') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[15] The equivalent resistance when a resistor of (1/3)Ω is connected in parallel with a (1/4)Ω resistance is:</span><br />
(a) 1/7 Ω<br />
(b) 7Ω<br />
(c) 1/12 Ω<br />
(d) 3/4 Ω</div>
<div id="spoiler15" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler15') .style.display=='none')
{document.getElementById('spoiler15') .style.display=''}
else{document.getElementById('spoiler15') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
The solutions with explanations for the problems are given in the link: <a href="http://www.electricalbasicprojects.com/wp-content/uploads/2015/09/Part-17-Quiz-solutions.pdf" target="_blank">Part-17 Problems and solutions</a><br />
Thanks for reading.. Please leave your comments below...
</div>
Anonymoushttp://www.blogger.com/profile/04540939319476033259noreply@blogger.com26tag:blogger.com,1999:blog-5521862752163472752.post-1994640310689667602015-09-25T01:07:00.000-07:002015-09-25T01:07:20.297-07:00DC Machine Multiple Choice Questions with Solutions: Part-12<div dir="ltr" style="text-align: left;" trbidi="on">
<b><u>DC Motor DC Generator Multiple Choice Questions with Solutions:</u></b><br />
<br />
<span style="color: red;">[1] Which of the following statements is false?</span><br />
(a) A DC motor converts electrical energy to mechanical energy<br />
(b) The efficiency of a DC motor is the ratio input power to output power<br />
(c) A DC generator converts mechanical power to electrical power<br />
(d) The efficiency of a DC generator is the ratio output power to input power<br />
Options:<br />
1. C only<br />
2. C and D only<br />
3. B only<br />
4. None of the above<br />
<br />
<div id="spoiler1" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 3 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[2] If the speed of a DC machine is doubled and the flux remains constant, the generated e.m.f.</span><br />
(a) remains the same<br />
(b) is doubled<br />
(c) is halved<br />
(d) None of the above<br />
<br />
<div id="spoiler2" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[3] If the flux per pole of a shunt-wound DC generator is increased, and all other variables are kept the same, the speed</span><br />
(a) decreases<br />
(b) stays the same<br />
(c) increases<br />
(d) None of the above<br />
<br />
<div id="spoiler3" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<div>
<br /></div>
<span style="color: red;">[4] Which of the following statements is false?</span><br />
(a) A commutator is necessary as part of a DC motor to keep the armature rotating in the same direction<br />
(b) A commutator is necessary as part of a DC generator to produce unidirectional voltage at the terminals of the generator<br />
(c) The field winding of a DC machine is housed in slots on the armature<br />
(d) The brushes of a DC machine are usually made of carbon and do not rotate with the armature<br />
Options:<br />
1. D only<br />
2. C and D only<br />
3. None of the above<br />
4. C only<br />
<br />
<div id="spoiler4" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 4 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[5] If the flux per pole of a shunt-wound DC generator is halved, the generated e.m.f. at constant speed</span><br />
(a) is doubled<br />
(b) is halved<br />
(c) remains the same<br />
(d) None of the above<br />
<br />
<div id="spoiler5" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[6] In a series-wound generator running at constant speed, as the load current increases, the terminal voltage</span><br />
(a) increases<br />
(b) decreases<br />
(c) stays the same<br />
(d) None of the above<br />
<br />
<div id="spoiler6" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[7] Which of the following statements is false for a series-wound DC motor?</span><br />
(a) The speed decreases with increase of resistance in the armature circuit<br />
(b) The speed increases as the flux decreases<br />
(c) The speed can be controlled by a diverter<br />
(d) The speed can be controlled by a shunt field regulator<br />
<br />
<div id="spoiler7" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[8] The armature resistance of a DC motor is 0.5 , the supply voltage is 200V and the back e.m.f. is 196V at full speed. The armature current is:</span><br />
(a) 4A<br />
(b) 8A<br />
(c) 400A<br />
(d) 392A<br />
<br />
<div id="spoiler8" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[9] In DC generators iron losses are made up of:</span><br />
(a) hysteresis and friction losses<br />
(b) hysteresis, eddy current and brush contact losses<br />
(c) hysteresis and eddy current losses<br />
(d) hysteresis, eddy current and copper losses<br />
<br />
<div id="spoiler9" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[10] The effect of inserting a resistance in series with the field winding of a shunt motor is to:</span><br />
(a) increase the magnetic field<br />
(b) increase the speed of the motor<br />
(c) decrease the armature current<br />
(d) reduce the speed of the motor<br />
<br />
<div id="spoiler10" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: #274e13;"><i><b>Thanks for reading... Please like us in the facebook and subscribe to get new posts to your mail id...</b></i></span></div>
Anonymoushttp://www.blogger.com/profile/04540939319476033259noreply@blogger.com26tag:blogger.com,1999:blog-5521862752163472752.post-37313317984031698222015-08-21T07:44:00.003-07:002015-08-21T07:44:44.229-07:003 Phase Induction Motors Objective Questions with Answers: Part-2<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="color: #274e13; font-size: small;"><u>3 Phase Induction Motors Related ( MCQ ) Objective Questions with Answers</u></span></h2>
<span style="color: red;"><b>[1] Which of the following statements about a three-phase squirrel-cage induction motor are false?</b></span><br />
(a) It has no external electrical connections to its rotor<br />
(b) A three-phase supply is connected to its stator<br />
(c) A magnetic flux which alternates is produced<br />
(d) It is cheap, robust and requires little or no skilled maintenance<br />
<br />
<span style="font-family: Courier New, Courier, monospace;">(1) A,B,C only</span><br />
<span style="font-family: Courier New, Courier, monospace;">(2) C and D only</span><br />
<span style="font-family: Courier New, Courier, monospace;">(3) C only</span><br />
<span style="font-family: Courier New, Courier, monospace;">(4) None of the above</span><br />
<span style="font-family: Courier New, Courier, monospace;">(5) B only</span><br />
<br />
<div id="spoiler1" style="display: none;">
<span style="text-align: left;"><b>Ans: 3 </b>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;"><b>[2] Which of the following statements about a three-phase induction motor </b></span><b style="color: red;">are</b><span style="color: red;"><b> false?</b></span><br />
(a) The speed of rotation of the magnetic field is called the synchronous speed<br />
(b) A three-phase supply connected to the rotor produces a rotating magnetic field<br />
(c) The rotating magnetic field has a constant speed and constant magnitude<br />
(d) It is essentially a constant speed type machine<br />
<br />
<span style="font-family: Courier New, Courier, monospace;">(1) C only</span><br />
<span style="font-family: Courier New, Courier, monospace;">(2) B only</span><br />
<span style="font-family: Courier New, Courier, monospace;">(3) A only</span><br />
<span style="font-family: Courier New, Courier, monospace;">(4) All of the above</span><br />
<span style="font-family: Courier New, Courier, monospace;">(5) A and C only</span><br />
<br />
<div id="spoiler2" style="display: none;">
<span style="text-align: left;"><b>Ans: 2 </b>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<b><span style="color: red;">[3] Which of the following statements is false when referring to a three-phase induction motor?</span></b><br />
(a) The synchronous speed is half the supply frequency when it has four poles<br />
(b) In a 2-pole machine, the synchronous speed is equal to the supply frequency<br />
(c) If the number of poles is increased, the synchronous speed is reduced<br />
(d) The synchronous speed is inversely proportional to the number of poles<br />
<br />
<span style="font-family: Courier New, Courier, monospace;">(1) All of the above</span><br />
<span style="font-family: Courier New, Courier, monospace;">(2) D only</span><br />
<span style="font-family: Courier New, Courier, monospace;">(3) B only</span><br />
<span style="font-family: Courier New, Courier, monospace;">(4) None of the above</span><br />
<span style="font-family: Courier New, Courier, monospace;">(5) A and C only</span><br />
<br />
<div id="spoiler3" style="display: none;">
<span style="text-align: left;"><b>Ans: 2 </b>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<b><span style="color: red;">[4] A 4-pole three-phase induction motor has a synchronous speed of 25 rev/s. The frequency of the supply to the stator is:</span></b><br />
(a) 50 Hz<br />
(b) 100 Hz<br />
(c) 25 Hz<br />
(d) 12.5 Hz<br />
<br />
<div id="spoiler4" style="display: none;">
<span style="text-align: left;"><b>Ans: A </b>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<b><span style="color: red;">[5] In a three-phase induction motor. Which </span></b><b><span style="color: red;">of the following </span></b><b><span style="color: red;">statements are false?</span></b><br />
(a) The slip speed is the synchronous speed minus the rotor speed<br />
(b) As the rotor is loaded, the slip decreases<br />
(c) The frequency of induced rotor e.m.f.’s increases with load on the rotor<br />
(d) The torque on the rotor is due to the interaction of magnetic fields<br />
<br />
<span style="font-family: Courier New, Courier, monospace;">(1) All of the above</span><br />
<span style="font-family: Courier New, Courier, monospace;">(2) C only</span><br />
<span style="font-family: Courier New, Courier, monospace;">(3) B only</span><br />
<span style="font-family: Courier New, Courier, monospace;">(4) A and C only</span><br />
<span style="font-family: Courier New, Courier, monospace;">(5) B and D only</span><br />
<br />
<div id="spoiler5" style="display: none;">
<span style="text-align: left;"><b>Ans: 3 </b>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<b><span style="color: red;">[6] In a three-phase induction motor. Which </span></b><b><span style="color: red;">of the following </span></b><b><span style="color: red;">statements are false?</span></b><br />
(a) If the rotor is running at synchronous speed, there is no torque on the rotor<br />
(b) If the number of poles on the stator is doubled, the synchronous speed is halved<br />
(c) At no-load, the rotor speed is very nearly equal to the synchronous speed<br />
(d) The direction of rotation of the rotor is opposite to the direction of rotation of the magnetic field to give maximum current induced in the rotor bars<br />
<br />
<span style="font-family: Courier New, Courier, monospace;">(1) A, B , C</span><br />
<span style="font-family: Courier New, Courier, monospace;">(2) C only</span><br />
<span style="font-family: Courier New, Courier, monospace;">(3) B only</span><br />
<span style="font-family: Courier New, Courier, monospace;">(4) A and C only</span><br />
<span style="font-family: Courier New, Courier, monospace;">(5) D only</span><br />
<br />
<div id="spoiler6" style="display: none;">
<span style="text-align: left;"><b>Ans: 5 </b>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;"><b>[7] The slip speed of an induction motor may be defined as the:</b></span><br />
(a) Number of pairs of poles ÷ frequency<br />
(b) Rotor speed - synchronous speed<br />
(c) Rotor speed + synchronous speed<br />
(d) Synchronous speed - rotor speed<br />
<br />
<div id="spoiler7" style="display: none;">
<span style="text-align: left;"><b>Ans:D </b>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;"><b>[8] The slip speed of an induction motor depends upon:</b></span><br />
(a) Armature current<br />
(b) Supply voltage<br />
(c) Mechanical load<br />
(d) Eddy currents<br />
<br />
<div id="spoiler8" style="display: none;">
<span style="text-align: left;"><b>Ans: C </b>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<b><span style="color: red;">[9] The starting torque of a simple squirrel-cage motor is:</span></b><br />
(a) Low<br />
(b) Increases as rotor current rises<br />
(c) Decreases as rotor current rises<br />
(d) High<br />
<br />
<div id="spoiler9" style="display: none;">
<span style="text-align: left;"><b>Ans: A </b>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<b><span style="color: red;">[10] The slip speed of an induction motor:</span></b><br />
(a) is zero until the rotor moves and then rises slightly<br />
(b) is 100 per cent until the rotor moves and then decreases slightly<br />
(c) is 100 per cent until the rotor moves and then falls to a low value<br />
(d) is zero until the rotor moves and then rises to 100 per cent<br />
<br />
<div id="spoiler10" style="display: none;">
<span style="text-align: left;"><b>Ans: C </b>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> </div>
<br />
Please leave your comments below....</div>
Anonymoushttp://www.blogger.com/profile/04540939319476033259noreply@blogger.com12tag:blogger.com,1999:blog-5521862752163472752.post-36250159770276633932015-07-08T09:38:00.000-07:002015-07-08T09:39:02.463-07:00Multiple Choice Questions [MCQ] on Basic Electrical Engineering -Part16<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="color: #274e13; font-size: small;">Objective Type Questions on Basic Electrical Engineering -Part16</span></h2>
<span style="color: red;">[1] A 240V, 60W lamp has a working resistance of:</span><br />
(a) 1400Ω<br />
(b) 60Ω<br />
(c) 960Ω<br />
(d) 325Ω<br />
<div id="spoiler1" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[2] The symbol for the unit of temperature coefficient of resistance is:</span><br />
(a) Ω /°C<br />
(b)Ω<br />
(c) °C<br />
(d) Ω /Ω°C<br />
<div id="spoiler2" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[3] The length of a certain conductor of resistance 100Ω is doubled and its cross-sectional area is halved. Its new resistance is</span>:<br />
(a) 100Ω<br />
(b) 200Ω<br />
(c) 50Ω<br />
(d) 400Ω<br />
<div id="spoiler3" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D</b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[4] Voltage drop is the:</span><br />
(a) Maximum potential<br />
(b) Difference in potential between two points<br />
(c) Voltage produced by a source<br />
(d) Voltage at the end of a circuit<br />
<div id="spoiler4" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[5] The largest number of 100W electric light bulbs which can be operated from a 240V supply fitted with a 13A fuse is:</span><br />
(a) 2<br />
(b) 7<br />
(c) 31<br />
(d) 18<br />
<div id="spoiler5" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[6] When an atom loses an electron, the atom:</span><br />
(a) Becomes positively charged<br />
(b) Disintegrates<br />
(c) Experiences no effect at all<br />
(d) Becomes negatively charged<br />
<div id="spoiler6" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[7] The energy used by a 1.5kW heater in 5 minutes is:</span><br />
(a) 5 J<br />
(b) 450 J<br />
(c) 7500 J<br />
(d) 450 000 J<br />
<div id="spoiler7" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[8] The unit of resistivity is:</span><br />
(a) ohms<br />
(b) ohm millimetre<br />
(c) ohm metre<br />
(d) ohm/metre<br />
<div id="spoiler8" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[9] A resistor marked as4K7G indicates a value of:</span><br />
(a) 47Ω ±20%<br />
(b) 4.7Ω k ±20%<br />
(c) 0.47Ω ±10%<br />
(d) 4.7 kΩ ±2<br />
<div id="spoiler9" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[10] The resistance of a 2 km length of cable of cross-sectional area 2mm<sup>2</sup> and resistivity of 2×10<sup>-8</sup>Ω m is:</span><br />
(a) 0.02Ω<br />
(b) 20Ω<br />
(c) 0.02mΩ<br />
(d) 200Ω<br />
<div id="spoiler10" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[11] A piece of graphite has a cross-sectional area of 10mm<sup>2</sup>. If its resistance is 0.1Ω and its resistivity 10×10<sup>8</sup> Ωm, its length is:</span><br />
(a) 10 km<br />
(b) 10 cm<br />
(c) 10 mm<br />
(d) 10 m<br />
<div id="spoiler11" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler11') .style.display=='none')
{document.getElementById('spoiler11') .style.display=''}
else{document.getElementById('spoiler11') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[12] A nickel coil has a resistance of 13Ω at 50°C. If the temperature coefficient of resistance at 0°C is 0.006/ °C, the resistance at 0°C is:</span><br />
(a) 16.9Ω<br />
(b) 10Ω<br />
(c) 43.3Ω<br />
(d) 0.1Ω<br />
<div id="spoiler12" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler12') .style.display=='none')
{document.getElementById('spoiler12') .style.display=''}
else{document.getElementById('spoiler12') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[13] A coil of wire has a resistance of 10 at 0°C. If the temperature coefficient of resistance for the wire is 0.004/ °C, its resistance at 100°C is:</span><br />
(a) 0.4Ω<br />
(b) 1.4Ω<br />
(c) 14Ω<br />
(d) 10Ω<br />
<div id="spoiler13" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler13') .style.display=='none')
{document.getElementById('spoiler13') .style.display=''}
else{document.getElementById('spoiler13') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[14] A colour coding of red-violet-black on a resistor indicates a value of:</span><br />
(a) 27Ω ±20%<br />
(b) 270Ω<br />
(c) 270Ω ±20%<br />
(d) 27Ω ±10%<br />
<div id="spoiler14" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler14') .style.display=='none')
{document.getElementById('spoiler14') .style.display=''}
else{document.getElementById('spoiler14') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[15] An inductance of 10mH connected across a 100V, 50 Hz supply has an inductive reactance </span><span style="color: red;">of</span><br />
(a) 10π <br />
(b) 1000π <br />
(c) π <br />
(d) π H</div>
<div id="spoiler15" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler15') .style.display=='none')
{document.getElementById('spoiler15') .style.display=''}
else{document.getElementById('spoiler15') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> </div>
Anonymoushttp://www.blogger.com/profile/04540939319476033259noreply@blogger.com8tag:blogger.com,1999:blog-5521862752163472752.post-87191204602005997762015-04-10T10:52:00.000-07:002015-05-21T09:40:02.360-07:00Multiple Choice Questions with Answers on Power Electronics and Drives: Part15<div dir="ltr" style="text-align: left;" trbidi="on">
<div style="font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; line-height: 24px;">
<h2 style="text-align: left;">
<span data-mce-style="color: #ff0000;" style="color: #38761d; font-size: small;"><u>Multiple Choice Questions with Answers on Power Electronics and Drives</u></span></h2>
<div style="color: #333333; font-size: 16px;">
<span data-mce-style="color: #ff0000;" style="color: red;">[Q-1] Silicon based rectifiers are preferred than germanium based rectifiers because</span></div>
<div style="font-size: 16px;">
<span data-mce-style="color: #000000;" style="color: black;">(a) Si is available easily compared to Ge</span></div>
<div style="font-size: 16px;">
<span data-mce-style="color: #000000;" style="color: black;">(b) Only Si has a stable off state</span></div>
<div style="font-size: 16px;">
<span data-mce-style="color: #000000;" style="color: black;">(c) Ge is very temperature sensitive</span></div>
<div style="font-size: 16px;">
<span data-mce-style="color: #000000;" style="color: black;">(d) Si only has the characteristics α1 + α2 < 1 at low collector currents and reaches 1 at high currents</span></div>
<div style="font-size: 16px;">
<span data-mce-style="color: #000000;" style="color: black;">Which of the above statements are true?</span></div>
<div style="font-size: 16px;">
<span data-mce-style="color: #000000;" style="color: black;">Options:</span></div>
<div style="font-size: 16px;">
<span data-mce-style="color: #000000;" style="color: black;">1. A, B, D</span></div>
<div style="font-size: 16px;">
<span data-mce-style="color: #000000;" style="color: black;">2. B, D</span></div>
<div style="font-size: 16px;">
<span data-mce-style="color: #000000;" style="color: black;">3. B Only</span></div>
<div style="font-size: 16px;">
<span data-mce-style="color: #000000;" style="color: black;">4. D Only</span></div>
<div style="font-size: 16px;">
<span data-mce-style="color: #000000;" style="color: black;">5. None of the above options</span></div>
</div>
<div style="font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<div style="color: #333333;">
<div id="spoiler" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 2 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler') .style.display=='none')
{document.getElementById('spoiler') .style.display=''}
else{document.getElementById('spoiler') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span data-mce-style="color: #ff0000;" style="color: red;">[Q-2] In a triac,</span></div>
<span data-mce-style="color: #000000;" style="color: black;">(a) The triggering pulse to main terminal 1 should be of the same polarity as the anode potential between MT1 and MT2</span><br />
(b) The triggering pulse should be of opposite polarity to that of anode potential<br />
(c) When the triggering pulse is positive and anode is positive, it is operating in the first quadrant<br />
(d) When the triggering pulse is negative and anode is negative its sensitivity is highest.<br />
Which of the above statements are true?<br />
Options:<br />
1. A, D<br />
2. A, C<br />
3. C, D<br />
4. A, C, D<br />
5. None of the above options<br />
<div style="color: #333333;">
<span style="color: red;">
</span><br />
<div id="spoiler1" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: 4 </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[Q-3] In a single phase full wave SCR circuit with R, L load</span></div>
(a) Power is delivered to the source for firing angle of less than 90°<br />
(b) The scr changes from inverter to converter at α = 90°<br />
(c) The negative dc voltage is maximum at α = 180°<br />
(d) To turn off the scr, the maximum delay angle must be less than 180°<br />
Which of the above statements are true?<br />
Options:<br />
1. C, D<br />
2. C Only<br />
3. D Only<br />
4. A , B<br />
5. None of the above options<br />
<div style="color: #333333;">
<span style="color: red;">
</span><br />
<div id="spoiler2" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: 1 </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[Q-4] While comparing triac and scr,</span></div>
(a) Both are unidirectional devices<br />
(b) Triac requires more current for turn on than scr at a particular voltages<br />
(c) A triac has less time for turn off than SCR<br />
(d) Both are available with comparable voltage and current ratings<br />
Which of the above statements are true?<br />
Options:<br />
1. A, C<br />
2. B, C<br />
3. A, B<br />
4. D Only<br />
5. None of the above options<br />
<div style="color: #333333;">
<span style="color: red;">
</span><br />
<div id="spoiler4" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans:2 </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[Q-5] Which of the following statements are true</span></div>
(a) If the SCR, even with proper gate excitation and anode-cathode voltage does not conduct for a particular load resistance, then it would be necessary to decrease the load resistance to turn ON the SCR<br />
(b) The SCR would be turned OFF by voltage reversal of the applied anode-cathode ac supply of frequencies up to 30kHz<br />
(c) If the gate current of the SCR is increased, then the forward breakdown voltage will decrease<br />
Options<br />
1. A, B, C<br />
2. B, C<br />
3. A , C<br />
4. A, B<br />
5. None of the above options<br />
<div style="color: #333333;">
<span style="color: red;">
</span><br />
<div id="spoiler5" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: 3 </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[Q-6] Which of the following statements are true</span></div>
When gate triggering is employed, a SCR can withstand higher values of di/dt, if the<br />
1. Gate current is increased<br />
2. Rate of rise of gate current is increased<br />
3. Gate current is increased<br />
4. Rate of rise of gate current is decreased<br />
OPTIONS:<br />
(a) 3, 4<br />
(b) 1, 4<br />
(c) 2, 3<br />
(d) 1, 2<br />
(e) None of the above options<br />
<div style="color: #333333;">
<span style="color: red;">
</span><br />
<div id="spoiler6" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[Q-7] In a SCR based converter, the free wheeling diode is used to</span></div>
(a) Add to the conduction current of thyristors<br />
(b) Oppose the SCR conduction<br />
(c) Conduct current during the OFF period of the SCR<br />
(d) Protect the SCR by providing a shunt path<br />
<div id="spoiler7" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<i>Thanks for reading.... Please leave your comments below....Please subscribe to get new posts to your mail ID....</i></div>
</div>
Anonymoushttp://www.blogger.com/profile/04540939319476033259noreply@blogger.com2tag:blogger.com,1999:blog-5521862752163472752.post-31418034027269887032015-03-25T10:10:00.000-07:002015-05-21T10:01:41.806-07:00Power Electronics Objective Type Questions with Answers: Part-14<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px; text-align: left;">
<strong><span data-mce-style="text-decoration: underline;" style="text-decoration: underline;"><span data-mce-style="color: #008000; text-decoration: underline;" style="color: green;">Power Electronics Objective Questions and Answers</span></span></strong></h2>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: red;">[Q-1] When an inductance is inserted in the load circuit of SCR</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black;">(a) The turn on time of SCR is increased</span><br />
<span data-mce-style="color: #000000;" style="color: black;">(b) Output voltage is reduced for the same firing angle</span><br />
<span data-mce-style="color: #000000;" style="color: black;">(c) Conduction continues even after reversal of phase of input voltage</span><br />
<span data-mce-style="color: #000000;" style="color: black;">(d) A free wheeling diode is connected in such circuits</span><br />
<span data-mce-style="color: #000000;" style="color: black;">Which of the above statements are true?</span><br />
<span data-mce-style="color: #000000;" style="color: black;">(1) a, d</span><br />
<span data-mce-style="color: #000000;" style="color: black;">(2) b, c, d</span><br />
<span data-mce-style="color: #000000;" style="color: black;">(3) a, b, c,d</span><br />
<span data-mce-style="color: #000000;" style="color: black;">(4) c, d</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #ff0000;" style="color: red;">
</span><br />
<div id="spoiler1" style="display: none;">
<span data-mce-style="color: #ff0000;" style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: 3 </b></span>
</span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[Q-2] Snubber circuit is used to limit the rate of</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black;">(a) Rise of current</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black;">(b) Conduction period</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black;">(c) Rise of voltage across SCR</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black;">(d) None of the above</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: red;">
</span><br />
<div id="spoiler2" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[Q-3] The provision of a free wheeling diode across an inductive load is</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(a) To restore conduction angle on phase</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(b) To avoid negative reversal voltage drop</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(c) To reduce the PRV</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(d) None of the above</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #ff0000;" style="color: red;">
</span><br />
<div id="spoiler3" style="display: none;">
<span data-mce-style="color: #ff0000;" style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></span></div>
<span data-mce-style="color: #ff0000;" style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[Q-4] While working in series operation, equalising circuits are added across each SCR to provide uniform</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black;">(a) Current distribution</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black;">(b) Firing of SCRs</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black;">(c) Voltage distribution</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span data-mce-style="color: #000000;" style="color: black;">(d) None of the above</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: red;">
</span><br />
<div id="spoiler4" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[Q-5] When the SCR conducts, the forward voltage drop</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(a) Is 0.7V</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(b) Is 1 to 1.5V</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(c) Increases slightly with load current</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(d) Remains constant with load current</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">Which of the above statements are true?</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(1) a only</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(2) b, c</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(3) d only</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(4) a, c</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: red;">
</span><br />
<div id="spoiler5" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: 2 </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[Q-6] The latching current of a SCR is 18mA. Its holding current will be</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(a) 6mA</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(b) 18mA</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(c) 54mA</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(d) 12mA</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: green;"></span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">Exp: Latching Current = 3 x Holding Current</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: red;">
</span><br />
<div id="spoiler6" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[Q-7] The turn off time is longer than turn on time because</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(a) The anode and cathode junctions get reverse biased while gate junction is still forward biased</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(b) There is flow of reverse current</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(c) The gate pulse has been removed</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(d) The forward break over voltage is high.</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">Which of the above statements are true?</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(1) b, c</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(2) c, d</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(3) a, b</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(4) a, b, c, d</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: red;">
</span><br />
<div id="spoiler7" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: 3 </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[Q-8] The thyristor will turn on faster with</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(a) Pulse signal applied to the gate terminal of the SCR</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(b) Continuous signal applied to the gate terminal of the SCR</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(c) Both are same</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(d) Pulse signal but with minimum duration</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">Which of the above statements are true?</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(1) a only</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(2) b only</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(3) a, d</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(4) none of the above</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: red;">
</span><br />
<div id="spoiler8" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans:3 </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[Q-9] In an SCR,</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(a) The holding current is less than latching current</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(b) The holding current is greater than latching current</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(c) The two currents are equal</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(d) The latching current is about 3 times the holding current</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">Which of the above statements are true?</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(1) a only</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(2) d only</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(3) a, c, d</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(4) a, d</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(5) b only</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: red;">
</span><br />
<div id="spoiler9" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: 4 </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[Q-10] When a positive voltage is applied to the gate of a reverse biased SCR</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(a) It injects more electrons into junction J1</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(b) It increases reverse leakage current into anode</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(c) Heating of junction is unaffected</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(d) Failure of junctions occurs due to thermal runaway</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">Which of the above statements are true?</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(1) b only</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(2) a, b ,d</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(3) b, d</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: black;">(4) d only</span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<strong><span data-mce-style="color: #008000;" style="color: green;"></span></strong></div>
<div id="spoiler10" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: 3 </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: #351c75;"><br /></span></div>
<div style="color: #333333; font-family: Georgia, 'Times New Roman', 'Bitstream Charter', Times, serif; font-size: 16px; line-height: 24px;">
<span style="color: #351c75;">Thanks for reading...Please subscribe to get new posts to your mail id...</span></div>
</div>
Anonymoushttp://www.blogger.com/profile/04540939319476033259noreply@blogger.com0tag:blogger.com,1999:blog-5521862752163472752.post-33281650074062643552015-01-29T07:12:00.003-08:002015-02-16T06:22:16.999-08:00Multiple Choice Questions [MCQ] on Basic Electrical Engineering -Part15<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="color: #38761d; font-size: small;"><u>First year Engineering Basic Electrical Engineering Objective Questions</u></span></h2>
<span style="color: red;">[1] The coulomb is a unit of:</span><br />
(a) Energy<br />
(b) Voltage<br />
(c) Power<br />
(d) Quantity of electricity<br />
<div id="spoiler1" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[2] A charge of 240 C is transferred in 2 minutes. The current flowing is:</span><br />
(a) 480A<br />
(b) 120A<br />
(c) 2A<br />
(d) 8A<br />
<div id="spoiler2" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[3] A resistance of 50 kΩ has a conductance of:</span><br />
(a) 20S<br />
(b) 0.02S<br />
(c) 0.02 mS<br />
(d) 20 kS<br />
<div id="spoiler3" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[4] Which of the following statements is incorrect?</span><br />
(a) 1N = 1 kgm/s<sup>2</sup><br />
(b) 1V = 1 J/C<br />
(c) 30mA = 0.03A<br />
(d) 1 J = 1N/m<br />
<div id="spoiler4" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[5] The power dissipated by a resistor of 10 ohm when a current of 2A passes through it is:</span><br />
(a) 0.4W<br />
(b) 20W<br />
(c) 40W<br />
(d) 200W<br />
<div id="spoiler5" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<div>
<br /></div>
<div>
<span style="color: red;">[6] A mass of 1200g is accelerated at 200 cm/s<sup>2 </sup>by a force. The value of the force required is:</span><br />
(a) 2.4N<br />
(b) 2400N<br />
(c) 240 kN<br />
(d) 0.24N<br />
<div id="spoiler6" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[7] A current of 2A flows for 10 hour through a 100 ohm resistor. The energy consumed by the resistor is:</span><br />
(a) 0.5 kWh<br />
(b) 4 kWh<br />
(c) 2 kWh<br />
(d) 0.02 kWh<br />
<div id="spoiler7" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[8] The unit of quantity of electricity is the:</span><br />
(a) volt<br />
(b) coulomb<br />
(c) ohm<br />
(d) joule<br />
<div id="spoiler8" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[9] Electromotive force is provided by:</span><br />
(a) Resistance’s<br />
(b) A conducting path<br />
(c) An electric current<br />
(d) An electrical supply source<br />
<div id="spoiler9" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[10] The unit of current is the:</span><br />
(a) Volt<br />
(b) Coulomb<br />
(c) Joule<br />
(d) Ampere<br />
<div id="spoiler10" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[11] In order that work may be done:</span><br />
(a) Two wires are necessary<br />
(b) The circuit must have a switch<br />
(c) Coal must be burnt<br />
(d) A supply of energy is required<br />
<div id="spoiler11" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler11') .style.display=='none')
{document.getElementById('spoiler11') .style.display=''}
else{document.getElementById('spoiler11') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[12] The ohm is the unit of:</span><br />
(a) Charge<br />
(b) Resistance<br />
(c) Power<br />
(d) Current<br />
<div id="spoiler12" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler12') .style.display=='none')
{document.getElementById('spoiler12') .style.display=''}
else{document.getElementById('spoiler12') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[13] The unit of resistivity is:</span><br />
(a) ohms<br />
(b) ohm millimetre<br />
(c) ohm metre<br />
(d) ohm/metre<br />
<div id="spoiler13" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler13') .style.display=='none')
{document.getElementById('spoiler13') .style.display=''}
else{document.getElementById('spoiler13') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[14] Voltage drop is the:</span><br />
(a) Maximum potential<br />
(b) Difference in potential between two points<br />
(c) Voltage at the end of a circuit<br />
(d) Voltage produced by a source<br />
<div id="spoiler14" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler14') .style.display=='none')
{document.getElementById('spoiler14') .style.display=''}
else{document.getElementById('spoiler14') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[15] A 240V, 60W lamp has a working resistance of:</span><br />
(a) 1400 ohm<br />
(b) 60 ohm<br />
(c) 960 ohm<br />
(d) 325 ohm<br />
<div id="spoiler15" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler15') .style.display=='none')
{document.getElementById('spoiler15') .style.display=''}
else{document.getElementById('spoiler15') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: purple;"><b>Solution Hint:</b></span><br />[1] Units<br />Energy - Watt-hr<br />
Voltage - volts<br />
Power - watts<br />
[2] Current = Charge in <span style="background-color: white; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 16.5px; line-height: 23.1000003814697px;">coulomb/ Time in sec</span><br />
<span style="background-color: white; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 16.5px; line-height: 23.1000003814697px;">[3] Conductance = 1/Resistance</span><br />
<span style="background-color: white; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 16.5px; line-height: 23.1000003814697px;">[15] P = </span>V<sup>2</sup><span style="background-color: white; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 16.5px; line-height: 23.1000003814697px;">/R</span><br />
<span style="background-color: white; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 16.5px; line-height: 23.1000003814697px;"><br /></span>
<i><span style="color: purple;">Thanks for reading..</span></i></div>
</div>
Anonymoushttp://www.blogger.com/profile/04540939319476033259noreply@blogger.com4tag:blogger.com,1999:blog-5521862752163472752.post-50234951829015253232015-01-02T17:49:00.000-08:002015-01-02T17:49:10.912-08:00Objective Questions on Batteries with Answers<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="color: #274e13; font-size: small;"><u>Multi-Choice Questions [MCQ] with Answers from Batteries</u></span></h2>
<span style="color: red;">[1] A battery consists of</span><br />
(a) A cell<br />
(b) A circuit<br />
(c) A generator<br />
(d) A number of cells<br />
<div id="spoiler1" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Answer: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[2] The terminal potential difference of a cell of e.m.f. 2V and internal resistance 0.1Ω when supplying a current of 5A will be</span><br />
(a) 1.5V<br />
(b) 2V<br />
(c) 1.9 V<br />
(d) 2.5V<br />
<div id="spoiler2" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Answer: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[3] Five cells, each with an e.m.f. of 2V and internal resistance of 0.5Ω are connected in series. The resulting battery will have</span><br />
(a) An e.m.f. of 2V and an internal resistance of 0.5 Ω<br />
(b) An e.m.f. of 10V and an internal resistance of 2.5 Ω<br />
(c) An e.m.f. of 2V and an internal resistance of 0.1 Ω<br />
(d) An e.m.f. of 10V and an internal resistance of 0.1 Ω<br />
<div id="spoiler3" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Answer: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[4] If the five cells of question 3 are connected in parallel the resulting battery will have</span><br />
(a) An e.m.f. of 10V and an internal resistance of 2.5 Ω<br />
(b) An e.m.f. of 2V and an internal resistance of 0.5 Ω<br />
(c) An e.m.f. of 2V and an internal resistance of 0.1 Ω<br />
(d) An e.m.f. of 10V and an internal resistance of 0.1 Ω<br />
<div id="spoiler4" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Answer: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[5] Which of the following statements is false?</span><br />
(a) A Leclanché cell is suitable for use in torches<br />
(b) A nickel–cadmium cell is an example of a primary cell<br />
(c) A secondary cell may be recharged after use<br />
(d) When a cell is being charged its terminal p.d. exceeds the cell e.m.f.<br />
<div id="spoiler5" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Answer: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[6] Which of the following statements is false?</span><br />
When two metal electrodes are used in a simple cell, the one that is higher in the electrochemical series:<br />
(a) Tends to dissolve in the electrolyte<br />
(b) Is always the negative electrode<br />
(c) Reacts most readily with oxygen<br />
(d) Acts an an anode<br />
<div id="spoiler6" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Answer:D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[7] Five 2V cells, each having an internal resistance of 0.2Ω are connected in series to a load of resistance 14 Ω. The current flowing in the circuit is</span><br />
(a) 10A<br />
(b) 1.4A<br />
(c) 1.5A<br />
(d) 2/3A<br />
<div id="spoiler7" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Answer: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[8] For the circuit of question 7, the p.d. at the battery terminals is</span><br />
(a) 10V<br />
(b) 9(1/3)V<br />
(c) 0V<br />
(d) 10(2/3)V<br />
<div id="spoiler8" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Answer: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[9] Which of the following statements is true?</span><br />
(a) The capacity of a cell is measured in volts<br />
(b) A primary cell converts electrical energy into chemical energy<br />
(c) Galvanising iron helps to prevent corrosion<br />
(d) Apositive electrode is termed the cathode<br />
<div id="spoiler9" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Answer: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[10] The greater the internal resistance of a cell</span><br />
(a) The greater the terminal potential difference.<br />
(b) The less the e.m.f.<br />
(c) The greater the e.m.f.<br />
(d) The less the terminal potential difference.<br />
<div id="spoiler10" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Answer: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[11] The negative pole of a dry cell is made of</span><br />
(a) Carbon<br />
(b) Copper<br />
(c) Zinc<br />
(d) Mercury<br />
<div id="spoiler11" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Answer: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler11') .style.display=='none')
{document.getElementById('spoiler11') .style.display=''}
else{document.getElementById('spoiler11') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[12] The energy of a secondary cell is usually renewed</span><br />
(a) By passing a current through it<br />
(b) It cannot be renewed at all<br />
(c) By renewing its chemicals<br />
(d) By heating it<br />
<div id="spoiler12" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Answer: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler12') .style.display=='none')
{document.getElementById('spoiler12') .style.display=''}
else{document.getElementById('spoiler12') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[13] Which of the following statements is true?</span><br />
(a) A zinc carbon battery is rechargeable and is not classified as hazardous<br />
(b) A nickel cadmium battery is not rechargeable and is classified as hazardous<br />
(c) A lithium battery is used in watches and is not rechargeable<br />
(d) An alkaline manganese battery is used in torches and is classified as hazardous<br />
<div id="spoiler13" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Answer: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler13') .style.display=='none')
{document.getElementById('spoiler13') .style.display=''}
else{document.getElementById('spoiler13') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> </div>
Anonymoushttp://www.blogger.com/profile/04540939319476033259noreply@blogger.com2tag:blogger.com,1999:blog-5521862752163472752.post-85694799995411071302014-12-27T00:52:00.000-08:002014-12-27T00:52:40.294-08:00Measurements and Instrumentation Objective Questions with Answers: Part-9<div dir="ltr" style="text-align: left;" trbidi="on">
<div style="background-color: white; font-family: Verdana, Geneva, sans-serif; font-size: 12px; font-stretch: normal; margin: 0px 0px 1em; position: relative; text-align: left; text-transform: uppercase;">
<span style="color: #38761d; font-size: x-small;"><u><b>MEASUREMENTS AND INSTRUMENTATION OBJECTIVE QUESTIONS WITH ANSWERS</b></u></span></div>
<div>
<span style="color: red;">[1] A rectifier type instrument is connected to 100VDC and is operated in the DC measuring module reads</span><br />
(a) 111V<br />
(b) 90V<br />
(c) 50V<br />
(d) 100V<br />
<br />
<div id="spoiler1" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[2] A permanent magnet moving coil ammeter has a coil resistance of 99ohm and Full Scale Deflection(FSD) current of 0.1mA. Shunt resistance is 1 ohm. Current through the meter at 0.5 F.S.D is</span><br />
(a) 0.007mA<br />
(b) 0.05mA<br />
(c) 0.023mA<br />
(d) 0.1mA<br />
<br />
<div id="spoiler2" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[3] One single phase wattmeter operating on 230V and 5A for 5 hours makes 1940 revolutions. Meter constant in revolutions is 400. What is the power factor of the land?</span><br />
(a) 1<br />
(b) 0.84<br />
(c) 0.73<br />
(d) 0.65<br />
<br />
<div id="spoiler3" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[4] For power measurement of three phase circuit by two wattmeter method, when the value of power factor is less than 0.5 lagging</span><br />
(a) one of the wattmeters will read zero<br />
(b) both give the same readings<br />
(c) one of the wattmeter connections will have to be reversed<br />
(d) pressure coil of the wattmeter will become ineffective.<br />
<br />
<div id="spoiler4" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[5] When using ohmmeter, applied voltage is to be disconnected from the circuit because</span><br />
(a) Voltage source will increase resistance<br />
(b) Current will decrease resistance<br />
(c) the ohmmeter has its own internal battery<br />
(d) non of the above<br />
<br />
<div id="spoiler5" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[6] Which wave has the least form factor?</span><br />
(a) Square wave<br />
(b) Rectangular wave<br />
(c) Sine wave<br />
(d) Triangular wave<br />
<br />
<div id="spoiler6" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[7] With a sweep time 10ms across the screen the approx. horizontal sawtooth frequency will be</span><br />
(a) 50Hz<br />
(b) 100Hz<br />
(c) 1kHz<br />
(d) 500Hz<br />
<br />
<div id="spoiler7" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[8] A spring controlled indicating instrument has a deflection of 90deg for maximum current I. The corresponding deflection for a gravity controlled instrument is</span><br />
(a) 90°<br />
(b) 120°<br />
(c) 30°<br />
(d) 0°<br />
<br />
<div id="spoiler8" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[9] It is found that 10A current passes through a resistor of 10ohms. The resistor has 5% tolerance . The error in measurement of current can be as high as 5%. What is max error in measurement of power, calculated from measured value of I and the nominal value of resistor?</span><br />
(a) 100 W<br />
(b) 150W<br />
(c)50W<br />
(d) 200W<br />
<br />
<div id="spoiler9" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[10] A resistor of 10Kohms with 5% tolerance is connected in parallel with a 5Kohms resistor of 10% tolerance. What is the tolerance limit for the parallel network?</span><br />
(a) 5%<br />
(b) 6.67%<br />
(c) 10%<br />
(d) 8.33%<br />
<br />
<div id="spoiler10" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[11] The resistance offered to the passage of an in-varying current by a column of mercury at the temperature of melting ice of mass 14.4521 gms of uniform cross-sectional area and length 106.3cm is</span><br />
(a) Standard ohm<br />
(b) One international ohm<br />
(c) One ohm according to SI units<br />
(d) One ohm according to working standards</div>
<div id="spoiler11" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler11') .style.display=='none')
{document.getElementById('spoiler11') .style.display=''}
else{document.getElementById('spoiler11') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> </div>
adminhttp://www.blogger.com/profile/03959820607389481053noreply@blogger.com3tag:blogger.com,1999:blog-5521862752163472752.post-27046263029145559612014-11-18T00:14:00.000-08:002014-11-18T00:14:34.207-08:00Measurements Instruments Objective Questions with Answers: part-8<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="color: #274e13; font-size: small;"><u>Measurements and Instruments Objective Questions with Answers</u></span></h2>
<span style="color: red;">[1] The most preferred material for the control spring is</span><br />
(a) German silver<br />
(b) Platinum silver<br />
(c) Silicon bronze<br />
(d) Phosphor bronze<br />
<br />
<div id="spoiler1" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[2] A moving coil instrument is used as an ohmmeter. The indicating scale of the meter will be</span><br />
(a) Hyperbolic<br />
(b) Logarithmic<br />
(c) Linear<br />
(d) Inverse linear<br />
<br />
<div id="spoiler2" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[3] For high accuracy the meter has</span><br />
(a) Supporting mirror<br />
(b) Hand drawn scale<br />
(c) Printed scale<br />
(d) Scale with sharp pointer<br />
<br />
<div id="spoiler3" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[4] Among the voltages to various electrodes in a CRT the voltage is the highest on</span><br />
(a) Aquadag<br />
(b) Focusing anode<br />
(c) Deflection plates<br />
(d) PD anode<br />
<br />
<div id="spoiler4" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[5] In a free running oscilloscope the horizontal deflection system is driven by a ........ waveform</span><br />
(a) Step<br />
(b) Impulse<br />
(c) Ramp<br />
(d) DC<br />
<br />
<div id="spoiler5" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[6] A Lissajous patterns are used to measure</span><br />
(a) Voltage and frequency<br />
(b) Frequency and Phase shift<br />
(c) Frequency and amplitude distortion<br />
(d) Amplitude and flux<br />
<br />
<div id="spoiler6" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[7] The shunt used in milliammeter</span><br />
(a) will extend the range and reduce the meter resistance<br />
(b) will extend the range and increase the meter resistance<br />
(c) will decrease the range and meter resistance<br />
(d) will not affect the meter<br />
<br />
<div id="spoiler7" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[8] The electrostatic instruments can be used without serious loss of accuracy upto ......... frequency</span><br />
(a) 100Hz<br />
(b) 100kHz<br />
(c) 1 MHz<br />
(d) 10MHz<br />
<br />
<div id="spoiler8" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[9] In the case of PMMC rectifier type instruments, the deflecting torque is proportional to</span><br />
(a) Average value of AC current<br />
(b) RMS of AC<br />
(c) Instantaneous value<br />
(d) Peak value<br />
<br />
<div id="spoiler9" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[10] Inductance and capacitance in the electrostatic system of units has the dimensions of</span><br />
(a) mass<br />
(b) mass-time<br />
(c) mass length/time<br />
(d) length<br />
<br />
<div id="spoiler10" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[11] For the indicating instrument the preferred damping condition is</span><br />
(a) Critically damped<br />
(b) a damping coefficient of 0.8 to 1<br />
(c) Overdamped<br />
(d) Underdamped<br />
<br />
<div id="spoiler11" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler11') .style.display=='none')
{document.getElementById('spoiler11') .style.display=''}
else{document.getElementById('spoiler11') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[12] One international ohm is equal to</span><br />
(a) 1.00049 absolute ohm<br />
(b) 0.99951 absolute ohm<br />
(c) 0.969 absolute ohm<br />
(d) 1.049 absolute ohm<br />
<br />
<div id="spoiler12" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler12') .style.display=='none')
{document.getElementById('spoiler12') .style.display=''}
else{document.getElementById('spoiler12') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
Please leave your comments below...</div>
adminhttp://www.blogger.com/profile/03959820607389481053noreply@blogger.com2tag:blogger.com,1999:blog-5521862752163472752.post-86068950402498163142014-10-19T09:11:00.001-07:002014-11-07T08:02:59.622-08:00Measurements Instrumentation Objective Questions Answers: Part-7<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="color: #274e13; font-family: Georgia, Times New Roman, serif; font-size: small;"><u>Measurements Instrumentation Objective Questions with Answers</u></span></h2>
<span style="color: red;">[1] A mulliammeter can be used as</span><br />
(a) Voltmeter and ammeter<br />
(b) Wattmeter<br />
(c) Ohmmeter<br />
(d) Frequency meter<br />
<div id="spoiler1" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[2] Which instrument has identical calibration for ac as well as dc values?</span><br />
(a) Hot wire type<br />
(b) Moving coil type<br />
(c) Induction type<br />
(d) Moving iron type<br />
<div id="spoiler2" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[3] An instrument to be used for measurement and control should preferably have</span><br />
(a) Dead zone and dead time<br />
(b) Linear output and fast response<br />
(c) Non-linear output<br />
(d) A highly damped response<br />
<div id="spoiler3" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[4] The current coil of a wattmeter is connected to the CT of R-phase. The potential coil </span><span style="color: red;">is connected across Y and B phases. The wattmeter measures</span><br />
(a) Active power in R phase<br />
(b) Active power of Y phase<br />
(c) Reactive power of R phase<br />
(d) Power proportional to 3 phase power if the load is balanced<br />
<div id="spoiler4" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[5] The problem of Electro-static coupling in a transformer is acute at</span><br />
(a) Low frequencies<br />
(b) Power frequencies<br />
(c) High frequencies<br />
(d) High load on the transformer<br />
<div id="spoiler5" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[6] Which meter is suitable for the measurement of 10mV at 50MHz?</span><br />
(a) Moving iron voltmeter<br />
(b) VTVM<br />
(c) Moving coil voltmeter<br />
(d) CRO<br />
<div id="spoiler6" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[7] It can be stated that</span><br />
(a) CT operates at almost the same flux density as a PT<br />
(b) CT operates with a higher flux density than PT<br />
(c) CT operates with considerably lower flux density than a PT<br />
(d) no generalisation can be made with regard to the flux densities in CT and PT<br />
<div id="spoiler7" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[8] The thermocouple instruments do not have</span><br />
(a) High sensitivity<br />
(b) Absence of frequency error<br />
(c) Independence of ambient temperature<br />
(d) High degree of measuring accuracy<br />
<div id="spoiler8" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[9] Some wire- wound resistors have bifilar winding. This type of winding is used to</span><br />
(a) Increase the thermal stability<br />
(b) Reduce the tolerance<br />
(c) Reduce the inductance of winding<br />
(d) Double the power rating of the resistor<br />
<div id="spoiler9" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[10] Wien bridge is useful for measuring</span><br />
(a) Very high frequency<br />
(b) Low frequency<br />
(c) Medium frequency<br />
(d) High frequency<br />
<div id="spoiler10" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[11] A megger is usually</span><br />
<div>
(a) Moving iron type instrument<br />
(b) Electro-static type instrument<br />
(c) Hot-wire type instrument<br />
(d) Moving coil type instrument<br />
<div id="spoiler11" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler11') .style.display=='none')
{document.getElementById('spoiler11') .style.display=''}
else{document.getElementById('spoiler11') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[12] A moving iron ammeter may be compensated for frequency errors by</span><br />
(a) a shunt resistance<br />
(b) a series inductance<br />
(c) shunt capacitance<br />
(d) series resistance<br />
<div id="spoiler12" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler12') .style.display=='none')
{document.getElementById('spoiler12') .style.display=''}
else{document.getElementById('spoiler12') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[13] Ryall crest voltmeter is used for measurement of</span><br />
(a) AC voltage of any form<br />
(b) Low frequency voltage<br />
(c) High DC voltage<br />
(d) High AC voltage<br />
<div id="spoiler13" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler13') .style.display=='none')
{document.getElementById('spoiler13') .style.display=''}
else{document.getElementById('spoiler13') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[14] Jewels are used in instruments for the purpose of</span><br />
(a) Damping<br />
(b) Torque control<br />
(c) Suppressing noise<br />
(d) Bearing<br />
<div id="spoiler14" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler14') .style.display=='none')
{document.getElementById('spoiler14') .style.display=''}
else{document.getElementById('spoiler14') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[15] The thermocouple instrument will measure</span><br />
(a) Current<br />
(b) Voltage<br />
(c) Flux<br />
(d) None of the above<br />
<div id="spoiler15" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler15') .style.display=='none')
{document.getElementById('spoiler15') .style.display=''}
else{document.getElementById('spoiler15') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> </div>
</div>
adminhttp://www.blogger.com/profile/03959820607389481053noreply@blogger.com2tag:blogger.com,1999:blog-5521862752163472752.post-82669879222297368232014-10-01T09:51:00.002-07:002014-10-19T09:53:42.796-07:00Basic electronics Multiple Choice Questions: Part-6<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="font-family: Arial, Helvetica, sans-serif; font-size: small;"><u>Basic electronics Multiple Choice Questions: Part-6</u></span></h2>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">[1] A network designed to pass signals with all frequencies except those between two specified cut-off frequencies is called a</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) low-pass filter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) high-pass filter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) band-pass filter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) band-stop filter</span><br />
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">
</span><br />
<div id="spoiler1" style="display: none;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></span></div>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[2] A low-pass T-connected symmetrical filter section has an inductance of 200mH in each of its series arms and a capacitance of 0.5 μF in its shunt arm. The cut-off frequency of the filter is</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 1007 Hz</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 251.6 Hz</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) 711.8 Hz</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) 177.9 Hz</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;">
</span></span><br />
<div id="spoiler2" style="display: none;">
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></span></span></div>
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[3] A low-pass π-connected symmetrical filter section has an inductance of 200mH in its series arm and capacitances of 400 pF in each of its shunt arms. The cut-off frequency of the filter is</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 25.16 kHz</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 6.29 kHz</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) 17.79 kHz</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) 35.59 kHz</span><br />
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">
</span><br />
<div id="spoiler3" style="display: none;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans:A </b></span>
</span></span></div>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[4] A high-pass T-connected symmetrical filter section has capacitances of 400 nF in each of its series arms and an inductance of 200mH in its shunt arm. The cut-off frequency of the filter is</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 1592 Hz</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 1125 Hz</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) 281 Hz</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) 398 Hz</span><br />
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">
</span><br />
<div id="spoiler4" style="display: none;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans:D </b></span>
</span></span></div>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[5] A high-pass π-connected symmetrical filter section has a capacitance of 5000 pF in its series arm and inductances of 500 μH in each of its shunt arms. The cut-off frequency of the filter is</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 201.3 kHz</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 71.18 kHz</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) 50.33 kHz</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) 284.7 kHz</span><br />
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">
</span><br />
<div id="spoiler5" style="display: none;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans:B </b></span>
</span></span></div>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[6] A network designed to pass signals at frequencies above a specified cut-off frequency is called a</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) low-pass filter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) high-pass filter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) band-pass filter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) band-stop filter</span><br />
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">
</span><br />
<div id="spoiler6" style="display: none;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></span></div>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[7] A network designed to pass signals at frequencies below a specified cut-off frequency is called a</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) low-pass filter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) high-pass filter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) band-pass filter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) band-stop filter</span><br />
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">
</span><br />
<div id="spoiler7" style="display: none;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></span></div>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[8] A network designed to pass signals with frequencies between two specified cut-off frequencies is called a</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) low-pass filter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) high-pass filter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) band-pass filter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) band-stop filter</span></div>
<div id="spoiler8" style="display: none;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></span></div>
<span style="font-family: Arial, Helvetica, sans-serif;"> <span style="color: red; text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="font-family: Arial, Helvetica, sans-serif;">The following refers to questions 9 and 10.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">A filter section is to have a nominal impedance of 620 and a cut-off frequency of 2 MHz.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">
[9] A low-pass T-connected symmetrical filter section is comprised of</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 98.68 μH in each series arm, 128.4 pF in shunt arm</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 49.34 μH in each series arm, 256.7 pF in shunt arm</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) 98.68 μH in each series arm, 256.7 pF in shunt arm</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) 49.34 μH in each series arm, 128.4 pF in shunt arm</span><br />
</span><br />
<div id="spoiler9" style="display: none;">
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><b>Ans: B </b>
</span></span></span></div>
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="font-family: Arial, Helvetica, sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br /><span style="color: red;">
[10] A low-pass π-connected symmetrical filter section is comprised of</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 98.68 μH in each series arm, 128.4 pF in shunt arm</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 49.34 μH in each series arm, 256.7 pF in shunt arm</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) 98.68 μH in each series arm, 256.7 pF in shunt arm</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) 49.34 μH in each series arm, 128.4 pF in shunt arm</span><br />
</span><br />
<div id="spoiler10" style="display: none;">
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><b>Ans: A </b>
</span></span></div>
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="font-family: Arial, Helvetica, sans-serif;">Please leave your comments...</span></span>
</div>
adminhttp://www.blogger.com/profile/03959820607389481053noreply@blogger.com4tag:blogger.com,1999:blog-5521862752163472752.post-74221439358148374452014-08-27T20:33:00.003-07:002014-10-19T10:04:43.477-07:00Measurements Instrumentation Objective Questions Answers: Part-6<div dir="ltr" style="text-align: left;" trbidi="on">
<span style="color: #274e13;"><b><u>MCQ in Electrical Measurements and Instrumentation</u></b></span><br />
<br />
<span style="color: red;">[1] A 10MHz CRO has</span><br />
(a) 5MHz sweep<br />
(b) 10MHz vertical oscillator<br />
(c) 10MHz horizontal oscillator<br />
(d) 10MHz supply frequency<br />
<div id="spoiler1" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
<span style="color: red;">[2] Which of the following instruments can be used to measure AC current only?</span><br />
(a) Permanent Magnet Type ammeter<br />
(b) Induction type ammeter<br />
(c) Moving iron voltmeter<br />
(d) Moving iron ammeter<br />
Answers:<br />
1. D only<br />
2. B only<br />
3. A, B, D<br />
4. B and D only<br />
<span style="color: red;">
</span><br />
<div id="spoiler2" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: 2 </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[3] An oscilloscope indicates</span><br />
(a) Peak to peak value of voltage<br />
(b) DC value of voltage<br />
(c) RMS value<br />
(d) Average value<br />
<span style="color: red;">
</span><br />
<div id="spoiler3" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[4] In a ballistic galvanometer, the deflecting torque is proportional to</span><br />
(a) the current through coil<br />
(b) square of current through coil<br />
(c) square-root of current through coil<br />
(d) sine of measured<br />
<span style="color: red;">
</span><br />
<div id="spoiler4" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans:A </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[5] The error of an instrument is normally given as a percentage of</span><br />
(a) measured value<br />
(b) full-scale value<br />
(c) mean value<br />
(d) rms value<br />
<span style="color: red;">
</span><br />
<div id="spoiler5" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[6] If the instrument is to have a wide range, the instrument should have</span><br />
(a) Linear scale<br />
(b) Square-law scale<br />
(c) Exponential scale<br />
(d) Logarithmic scale<br />
<span style="color: red;">
</span><br />
<div id="spoiler6" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans:D </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[7] The resistance can be measured most accurately by</span><br />
(a) Voltmeter-ammeter method<br />
(b) bridge method<br />
(c) multimeter<br />
(d) Megger<br />
<span style="color: red;">
</span><br />
<div id="spoiler7" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[8] The repeat accuracy of an instrument can be judged from its</span><br />
(a) static error<br />
(b) linearity error<br />
(c) dynamic error<br />
(d) standard deviation of error<br />
<span style="color: red;">
</span><br />
<div id="spoiler8" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[9] Which of the following meters has a linear scale?</span><br />
(a) Thermocouple meter<br />
(b) Moving iron meter<br />
(c) Hot wore meter<br />
(d) Moving coil meter<br />
<span style="color: red;">
</span><br />
<div id="spoiler9" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[10] No eddy current and hysteresis losses occur in</span><br />
(a) Electrostatic instruments<br />
(b) PMMC instruments<br />
(c) Moving iron instruments<br />
(d) Electrodynamo meter instruments<br />
<span style="color: red;">
</span><br />
<div id="spoiler10" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[11] Two voltmeters have the same range 0-400V. The internal impedance are 30,000 Ohms and 20,000 Ohms. If they are connected in series and 600V be applied across them, the readings are</span><br />
(a) 360V and 240V<br />
(b) 300V each<br />
(c) 400V and 200V<br />
(d) one of the meters out of the range and other 100V<br />
<div>
<span style="color: red;">
</span><br />
<div id="spoiler11" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler11') .style.display=='none')
{document.getElementById('spoiler11') .style.display=''}
else{document.getElementById('spoiler11') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[12] The full-scale deflection current of an ammeter is 1 mA and its internal resistance is 100Ohm. If this meter is to have full deflection at 5A, what is the value of the shunt resistance to be used?</span><br />
(a) 49.99 Ohms<br />
(b) 1/49.99 ohms<br />
(c) 1 Ohm<br />
(d) 2 Ohms<br />
<span style="color: red;">
</span><br />
<div id="spoiler12" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler12') .style.display=='none')
{document.getElementById('spoiler12') .style.display=''}
else{document.getElementById('spoiler12') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[13] The full-scale deflection current of an ammeter is 1 mA and its internal resistance is 100Ohm. This is to have full deflection when 100V is measured. What is the value of series resistor to be used?</span><br />
(a) 99.99 K ohms<br />
(b) 100 K ohms<br />
(c) 99.99 ohms<br />
(d) 100 ohms<br />
<span style="color: red;">
</span><br />
<div id="spoiler13" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler13') .style.display=='none')
{document.getElementById('spoiler13') .style.display=''}
else{document.getElementById('spoiler13') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[14] Why is a MISC meter not recommended for DC measurement?</span><br />
(a) The meter is calibrated for AC and it's error for DC would be high<br />
(b) The meter does not respond to DC signals<br />
(c) The error is high due to hysteresis effect<br />
(d) The error is high due to eddy current effect<br />
<span style="color: red;">
</span><br />
<div id="spoiler14" style="display: none;">
<span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></span></div>
<span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler14') .style.display=='none')
{document.getElementById('spoiler14') .style.display=''}
else{document.getElementById('spoiler14') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[15] The EMF of Weston standard cell is measured using</span><br />
(a) Moving- iron meter<br />
(b) Moving-coil meter<br />
(c) Digital Volt meter<br />
(d) Potentiometer<br />
<div id="spoiler15" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler15') .style.display=='none')
{document.getElementById('spoiler15') .style.display=''}
else{document.getElementById('spoiler15') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
Please leave your comments below...</div>
<br /></div>
adminhttp://www.blogger.com/profile/03959820607389481053noreply@blogger.com3tag:blogger.com,1999:blog-5521862752163472752.post-14701703407775542952014-08-07T09:22:00.000-07:002014-08-07T09:22:05.067-07:00Measurements Instrumentation Objective Questions Answers: Part-5<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="color: #274e13; font-size: small;"><u>Objective Questions from Measurements Instrumentation </u></span></h2>
<span style="color: red;">[1] A CRO can display</span><br />
(a) AC signals<br />
(b) DC signals<br />
(c) Both AC and DC signals<br />
(d) Time invariant signals<br />
<br />
<div id="spoiler1" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[2] The internal resistance of an ammeter should be</span><br />
(a) Very small<br />
(b) medium<br />
(c) High<br />
(d) Infinity<br />
<br />
<div id="spoiler2" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[3] A galvanometer has</span><br />
(a) air friction damping<br />
(b) fluid friction damping<br />
(c) Spring coil damping<br />
(d) Eddy current damping<br />
<br />
<div id="spoiler3" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[4] Electrostatic instruments are normally used for</span><br />
(a) Low current measurements<br />
(b) High current measurements<br />
(c) Low voltage measurements<br />
(d) High voltage measurements<br />
<br />
<div id="spoiler4" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[5] In a moving coil instrument, the deflecting torque is proportional to</span><br />
(a) Current<br />
(b) Square of the current<br />
(c) Squareroot of the current<br />
(d) sine of the measurand<br />
<br />
<div id="spoiler5" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[6] The absolute measurement of resistance is done by</span><br />
(a) Ohm's law method<br />
(b) Bridge Method<br />
(c) Rayleigh method<br />
(d) Lorenz method<br />
<br />
<div id="spoiler6" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[7] To measure the flux, devices used are based on</span><br />
(a) Voltaic effect<br />
(b) Piezo-electric effect<br />
(c) Hall effect<br />
(d) Photo-voltaic effect<br />
<br />
<div id="spoiler7" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[8] The form factor in AC is the ratio of</span><br />
(a) peak value to average value<br />
(b) peak value to rms value<br />
(c) rms value to average value<br />
(d) rms value to peak value<br />
<br />
<div id="spoiler8" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[9] PMMC type instruments normally use</span><br />
(a) Air friction damping<br />
(b) Fluid friction damping<br />
(c) Eddy current damping<br />
(d) None of the above<br />
<br />
<div id="spoiler9" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[10] In a moving iron meter, the deflecting torque is proportional to</span><br />
(a) Current through the coil<br />
(b) Square of the current through the coil<br />
(c) Sine of the measurand<br />
(d) Squareroot of the measurand<br />
<br />
<div id="spoiler10" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[11] In a gravity controlled instrument, the deflection angle is proportional</span><br />
(a) Measurand<br />
(b) Square of the measurand<br />
(c) sine inverse of measurand<br />
(d) sine of the measurand<br />
<br />
<div id="spoiler11" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler11') .style.display=='none')
{document.getElementById('spoiler11') .style.display=''}
else{document.getElementById('spoiler11') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[12] Ampere is one of the</span><br />
(a) Supplementary units<br />
(b) Derived units<br />
(c) Base units<br />
(d) Units used to measure charge<br />
<br />
<div id="spoiler12" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler12') .style.display=='none')
{document.getElementById('spoiler12') .style.display=''}
else{document.getElementById('spoiler12') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red;">[13] Direct method is used to measure</span><br />
(a) Length<br />
(b) Temperature<br />
(c) Pressure<br />
(d) Voltage<br />
<br />
<div id="spoiler13" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler13') .style.display=='none')
{document.getElementById('spoiler13') .style.display=''}
else{document.getElementById('spoiler13') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<br />
Please leave your comments and questions below...</div>
adminhttp://www.blogger.com/profile/03959820607389481053noreply@blogger.com0tag:blogger.com,1999:blog-5521862752163472752.post-72035755230660993022014-06-12T09:31:00.000-07:002014-07-23T10:19:03.108-07:00Basic Electrical objective type questions: Part-13<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;"><u><b>Electrical Objective Questions with Answers:</b></u></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: red;">[1] In a uniform electric field, field lines and equipotentials [Gate 1997 ]</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">a) Are parallel to one another</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">b) Intersect at 45 deg</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">c) Intersect at 30 deg</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">d) Are orthogonal</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="color: #274e13;"><b></b></span></span>
<div id="spoiler1" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:D </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">[2] For a pulse transformer, the material used for its core and the possible turn ratio from primay to secondary are respectively</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) ferrite; 20:1</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) laminated iron; 1:1</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) ferrite; 1:1</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) powdered iron; 1:1</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="color: #274e13;"><b></b></span></span>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">
</span><br />
<div id="spoiler2" style="display: none;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></span></div>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[3] The capacitance of a reverse biased junction of a thyristor is 20 picofarad. The charging current of this thyristor is 4mA. The limiting value</span><br />
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">of dv/dt is .....V/uS</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="color: #274e13;"><b></b></span></span>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">
</span><br />
<div id="spoiler3" style="display: none;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans:200 </b></span>
</span></span></div>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[4] When the induction motor runs at synchronous speed the voltage induced in the rotor of it is</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Very near input voltage to stator</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Slip time the input voltage</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Zero</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) None of the above</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="color: #274e13;"><b></b></span></span>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">
</span><br />
<div id="spoiler4" style="display: none;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans:C </b></span>
</span></span></div>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[5] Chopper control for the DC motor provides variation in</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Input voltage</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Frequency</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) None of the above</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="color: #274e13;"><b></b></span></span>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">
</span><br />
<div id="spoiler5" style="display: none;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></span></div>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[6] While comparing SCR with BJT, which of the following is true</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) SCR requires turn off circuit while BJT does not</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) The voltage drop of SCR is less than BJT</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) SCR requires a continuous gate current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) BJT draws continuously base current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">Which of the above statements are true?</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(1) a only</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(2) d only</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(3) a, d</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(4) b, d</span><br />
<br />
<span style="font-family: Arial, Helvetica, sans-serif;">
Common Data Questions: 7 & 8<b> </b></span><br />
<div style="text-align: justify;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">In the 3-phase inverter circuit shown, the load is balanced and the gating scheme is 180°-conduction mode.All the switching devices are ideal</span></div>
<div style="color: #cc0000; text-align: justify;">
<div class="separator" style="clear: both;">
<span style="font-family: Arial, Helvetica, sans-serif;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAqJ1-GhO9caIU-rDKj1syGE8FoC5YGsowYMQFrdJ7q8oWIiPu_wD6wOQGQ7aPm4RnoKMa14IxJnyXUUykKV6iEbW0GmweE5dv0cdApwjDsNZcSluQBJNesTVrxVjQVj5CAnzqDa_tNBvA/s320/50.png" height="187" width="320" /></span></div>
</div>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">
</span><br />
<div id="spoiler6" style="display: none;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: 3 </b></span>
</span></span></div>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[7] The rms value of load phase voltage is [GATE2012]</span><br />
<div style="text-align: justify;">
<span style="font-family: Arial, Helvetica, sans-serif;">a. 106.1V</span></div>
<div style="text-align: justify;">
<span style="font-family: Arial, Helvetica, sans-serif;">b. 141.4V</span></div>
<div style="text-align: justify;">
<span style="font-family: Arial, Helvetica, sans-serif;">c. 212.2V</span></div>
<div style="text-align: justify;">
<span style="font-family: Arial, Helvetica, sans-serif;">d. 282.8V</span><br />
<div>
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="color: #274e13;"><b></b></span></span>
<div style="color: #cc0000;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">
</span><br />
<div id="spoiler7" style="display: none;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></span></div>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[8] If the dc bus voltage V<sub>d</sub>=300V, the power consumed by 3-phase load is </span><span style="color: red; font-family: Arial, Helvetica, sans-serif; text-align: left;"> </span><span style="color: red; font-family: Arial, Helvetica, sans-serif; text-align: left;">[GATE2012]</span></div>
</div>
</div>
<div style="text-align: justify;">
<span style="font-family: Arial, Helvetica, sans-serif;">a. 1.5kW</span></div>
<div style="text-align: justify;">
<span style="font-family: Arial, Helvetica, sans-serif;">b. 2.0kW</span></div>
<div style="text-align: justify;">
<span style="font-family: Arial, Helvetica, sans-serif;">c. 2.5kW</span></div>
<div style="text-align: justify;">
<span style="font-family: Arial, Helvetica, sans-serif;">d. 3.0kW</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="color: #274e13;"><b></b></span></span>
<div style="text-align: left;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">
</span><br />
<div id="spoiler8" style="display: none;">
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></span></div>
<span style="color: red; font-family: Arial, Helvetica, sans-serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[9] The typical ratio of latching current to holding current in a 20A thyristor is [GATE 2012]</span></div>
<div>
<span style="font-family: Arial, Helvetica, sans-serif;">a. 5.0</span></div>
<div>
<span style="font-family: Arial, Helvetica, sans-serif;">b. 2.0</span></div>
<div>
<span style="font-family: Arial, Helvetica, sans-serif;">c. 1.0</span></div>
<div>
<span style="font-family: Arial, Helvetica, sans-serif;">d. 0.5</span><br />
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;"><b></b></span></div>
<div>
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="color: red;">
</span></span><br />
<div id="spoiler9" style="display: none;">
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></span></span></div>
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[10] A half-controlled single-phase bridge rectifier is supplying an R-L load. It is operated at a firing angle α and the load current is continuous. The fraction of cycle that the freewheeling diode conducts is [GATE 2012]</span></span></div>
<div>
<span style="font-family: Arial, Helvetica, sans-serif;">a. 1/2</span></div>
<div>
<span style="font-family: Arial, Helvetica, sans-serif;">b. (1-α/π)</span></div>
<div>
<span style="font-family: Arial, Helvetica, sans-serif;">c. α/2π</span></div>
<div>
<span style="font-family: Arial, Helvetica, sans-serif;">d. α/π</span></div>
<div style="text-align: left;">
<b><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;"></span></b></div>
<b><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">
</span></b>
<br />
<div>
</div>
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;">
</span></span><br />
<div id="spoiler10" style="display: none;">
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: D </b></span>
</span></span></span></div>
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler10') .style.display=='none')
{document.getElementById('spoiler10') .style.display=''}
else{document.getElementById('spoiler10') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[11]</span><span style="color: red; text-indent: -0.25in;"> </span><span style="color: red; text-indent: -0.25in;">For power factor correction of power systems which one is used:</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="text-indent: -0.25in;">(a) capacitor</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="text-indent: -0.25in;">(b)</span><span style="text-indent: -0.25in;"> </span><span style="text-indent: -0.25in;">inductor</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="text-indent: -0.25in;">(c) resistors</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="color: #274e13;"><b></b></span></span>
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;">
</span></span><br />
<div id="spoiler11" style="display: none;">
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></span></span></div>
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler11') .style.display=='none')
{document.getElementById('spoiler11') .style.display=''}
else{document.getElementById('spoiler11') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[12] Which type of motor used in home ceiling fan:</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) capacitor motor </span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) shaded pole motor </span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) universal motor</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(SPLIT PHASE CAPACITOR MOTOR)</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;">
</span></span><br />
<div id="spoiler12" style="display: none;">
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></span></span></div>
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler12') .style.display=='none')
{document.getElementById('spoiler12') .style.display=''}
else{document.getElementById('spoiler12') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[13] Op-amp (operational amplifier) input resistance:</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Zero</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Infinity</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Relative resistance</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Same output resistance</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="color: #274e13;"><b></b></span></span>
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;">
</span></span><br />
<div id="spoiler13" style="display: none;">
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;"><span style="text-align: left;"><span style="color: green;"><b>Ans:B </b></span>
</span></span></span></div>
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: red;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler13') .style.display=='none')
{document.getElementById('spoiler13') .style.display=''}
else{document.getElementById('spoiler13') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[14] For an inverter op-amp, what will be the equivalent output resistance?</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Zero</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Infinity</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Relative forward resistance</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Same as the input resistance</span><br />
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;"><b></b></span></div>
</div>
<div id="spoiler14" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler14') .style.display=='none')
{document.getElementById('spoiler14') .style.display=''}
else{document.getElementById('spoiler14') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> </div>
adminhttp://www.blogger.com/profile/03959820607389481053noreply@blogger.com6tag:blogger.com,1999:blog-5521862752163472752.post-51790983151145653322014-02-05T20:23:00.000-08:002014-02-11T03:23:26.086-08:00Power Electronics Objective Type Questions: Part-13<div dir="ltr" style="text-align: left;" trbidi="on">
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;"><b><u>Power Electronics Multiple Choice Questions</u></b></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[1] During forward blocking state, the SCR has</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) </span><span style="font-family: Arial, Helvetica, sans-serif;">Low current, medium voltage</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Low current, large voltage</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Medium current, large voltage</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) </span><span style="font-family: Arial, Helvetica, sans-serif;">Large current, low voltage</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: B</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[2] Once SCR starts conducting a forward current, its gate loses control over</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) </span><span style="font-family: Arial, Helvetica, sans-serif;">Anode circuit current only</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) </span><span style="font-family: Arial, Helvetica, sans-serif;">Anode circuit voltage only</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Anode circuit voltage and current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Anode circuit voltage, current and time</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: C</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[3] In a SCRs</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) </span><span style="font-family: Arial, Helvetica, sans-serif;">Both Latching current and holding current are associated with turn-off process</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) </span><span style="font-family: Arial, Helvetica, sans-serif;">Latching current is associated with turn-off process and holding current with turn on process</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Holding current is associated with turn-off process and Latching current with turn-on process</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Both Latching current and holding current are associated with turn on process</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: C</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[4] The SCR can be termed as</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) DC switch</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) AC switch</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) </span><span style="font-family: Arial, Helvetica, sans-serif;">Square-wave switch</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) </span><span style="font-family: Arial, Helvetica, sans-serif;">Either A or B</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: A</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[5] In a thyristor, the magnitude of anode current will</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Increase if gate current is increased</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) </span><span style="font-family: Arial, Helvetica, sans-serif;">Increase if gate current is decreased</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) </span><span style="font-family: Arial, Helvetica, sans-serif;">Decrease if gate current is decreased</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Not change with any variation in gate current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: D</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[6] Turn on time of an SCR can be reduced by using a</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Rectangular pulse of high amplitude and narrow width</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Rectangular pulse of low amplitude and wide width</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Triangular pulse</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Trapezoidal pulse</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: A</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[7] Turn off time of an SCR in series with RL circuit can be reduced by</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Increasing circuit resistance R</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Decreasing circuit resistance R</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Increasing circuit inductance L</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Decreasing circuit inductance L</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">Options:</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">1) B, C</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">2) A, D</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">3) B, D</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">4) D only</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: 4</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[8] A forward voltage can be applied to an SCR after its</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Anode current reduces to zero</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Gate recovery time</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Reverse recovery time</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Anode voltage reduces to zero</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: B</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[9] Turn-off time of an SCR is measured from the instant</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Anode current becomes zero</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Anode voltage becomes zero</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Anode voltage and anode current become zero at the same time</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Gate current becomes zero</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: A</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[10] In an SCR, anode current flows over a narrow region near the gate during</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Delay time td</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Rise time tr and spread time tp</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) td and tp</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) td and tr</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: D</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[11] Gate characteristic of a thyristor</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Is straight line passing through origin</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Is of the type Vg = a + bIg</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Is a curve between Vg and Ig</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Has a spread between two curves of Vg-Ig</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: D</span><br />
<div>
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[12] Surge current rating of an SCR specified the maximum</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Repetitive current with sine wave</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Non-repetitive current with rectangular wave</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Non-repetitive current with sine wave</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Repetitive current with rectangular wave</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: C</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[13] The di/dt rating of an SCR is specified for its</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Decaying anode current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Decaying gate current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Rising gate current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Rising anode current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: D</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[14] For an SCR, dv/dt protection is achieved through the use of</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) RL in series with SCR</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) RC across</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) L in series with</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) RC in series with</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: B</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[15] For an SCR, di/dt protection is achieved through the use of</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) R in series with SCR</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) RL in series with SCR</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) L in series with SCR</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) L across SCR</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: C</span></div>
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;"><b><u>Solution Hint:</u></b></span><br />
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;">[4] SCR will allow current flow in one direction only. So the ideal SCR is similar to DC switch</span><br />
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;">[7] By the decreasing the Inductor L value, the di/dt is increasing. ie, fast turn off process</span><br />
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;">[14] Snubber circuit ( RC circuit across device) is used for dv/dt protection</span><br />
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;">[15] Inductor will oppose sudden change in current (di/dt). For inductor, series resistance is not required. But in snubber circuit, R is mandatory for dissipating the stored energy in the capacitor.</span></div>
Unknownnoreply@blogger.com4tag:blogger.com,1999:blog-5521862752163472752.post-9914942033897194682014-01-28T07:09:00.001-08:002014-02-11T03:40:52.322-08:00Power Electronics Multiple Choice Questions: Part-12<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="color: #38761d; font-family: Arial, Helvetica, sans-serif; font-size: small;"><u>Multiple Choice Questions Based on Power Electronics and Drives</u></span></h2>
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[1] When a line commutated converter operates in the inverter mode</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) It draws both real and reactive power from the AC supply</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) It delivers both real and reactive power to the AC supply</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) It delivers real power to the AC supply</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) It draws reactive power from the AC supply</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: C</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[2] A chopper operating at a fixed frequency is feeding an RL load. As the duty ratio of the chopper is increased from 25% to 75%, the ripple in the load current is</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Remains constant</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Decreases, reaches a minimum at 50% duty ratio and then increases</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Increases, reaches a maximum at 50% duty ratio and then decreases</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Keeps on increasing as the duty ratio is increased</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: A</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[3] To turn off a SCR, the reverse bias should be applied for a period ....... the turn-off time of the SCR</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Equal to </span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Longer than</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Less than</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Irrespective of</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: B</span></span><br />
<span style="color: red; font-family: Arial, Helvetica, sans-serif;">[</span><span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">4] In class A and class B commutation the resonating circuit has to be</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Over damped</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Critically damped</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Under damped</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Negatively damped</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: C</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[5] In phase controlled rectification power factor (PF)</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Remains unaffected</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Improves with increase of firing angle α</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Deteriorates with increase of α</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Is unrelated to α</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: C</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[6] Comparing with the full wave rectifier using two diodes, the four diode bridge rectifier has the dominant advantage of</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Higher current carrying </span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Lower peak inverse voltage requirement</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Lower ripple factor</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Higher efficiency</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: B</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[7] A SCR is rated at 75A peak, 20A average. The greatest possible delay in the trigger angle if the dc is at rated value is</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 47.5°</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 30° to 45°</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) 74.5°</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) 137°</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: B</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[8] The applied sine voltage to a SCR is V<span style="font-size: x-small; line-height: 17.982954025268555px;">M</span>=200V and R=10Ohm. If the gate trigger lags the ac supply by 120°, the average load current is</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 15/π A</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 5/π A</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) -5/π A</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) -15/π A</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: A</span></span><br />
<span style="color: #cc0000;"><span style="font-family: Arial, Helvetica, sans-serif;">[9] A sine voltage of 200Vrms, 50Hz is applied to an SCR through 100ohm resistor. The firing angle is 60°. Consider no voltage drop. The output </span><span style="font-family: Arial, Helvetica, sans-serif;">voltage in rms is</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 89.7 V</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 126.7 V</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) 166.7 V</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) 200√2 V</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: B</span></span><br />
<span style="color: #cc0000;"><span style="font-family: Arial, Helvetica, sans-serif;">[10] A 100V</span></span><span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif; font-size: 13px; line-height: 13.333333015441895px; text-align: justify;">DC</span><span style="color: #cc0000;"><span style="font-family: Arial, Helvetica, sans-serif;"> is applied to the inductive load through a SCR. The SCR's specified latching current is 100mA. The minimum required width of gating </span><span style="font-family: Arial, Helvetica, sans-serif;">pulse to turn on the SCR is</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 100μS</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 100S</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) 1mS</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) 50μS</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: A</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[11] A cycloconverter is a</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Frequency changer </span><span style="font-family: Arial, Helvetica, sans-serif;">from higher to lower frequency with one-state conversion</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) </span><span style="font-family: Arial, Helvetica, sans-serif;">Frequency changer </span><span style="font-family: Arial, Helvetica, sans-serif;">from higher to lower frequency with two-stage conversion</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) </span><span style="font-family: Arial, Helvetica, sans-serif;">Frequency changer </span><span style="font-family: Arial, Helvetica, sans-serif;">from lower to higher frequency with one-stage conversion</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Either a or c</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #38761d; font-family: Arial, Helvetica, sans-serif;">Answer: D</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: #cc0000;">[12] The cycloconverter require natural or forced commutation as under</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Natural commutationin bothstep-up and step down cycloconverter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Forced commutation in both step-up and step-down cycloconverter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Forced commutation in step-up cycloconverter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Forced commutation in step-down cycloconverter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #38761d; font-family: Arial, Helvetica, sans-serif;">Answer: C</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: #cc0000;">[13] In synchronized UJT triggering of an SCR, voltage V</span></span><span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif; font-size: 13px; line-height: 13.333333015441895px; text-align: justify;">C</span><span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: #cc0000;"> across capacitor reaches UJT threshold thrice in each half cycle so that there are three firing pulses during each half cycle. The firing angle of the SCR can be controlled</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Once in each half cycle</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Thrice in each half cycle</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Twice in each half cycle</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Four times in each half cycle</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(e) None of the above </span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #38761d; font-family: Arial, Helvetica, sans-serif;">Answer: A</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: #cc0000;">[14] In a GTO, anode current begins to fall when gate current</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Is negative peak at time t=0</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Is negative peak at t = storage period t</span><span style="font-family: Arial, Helvetica, sans-serif; font-size: 13px; line-height: 13.333333015441895px; text-align: justify;">S</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Just begins to become negative at t = 0</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Is negative peak at t = (t</span><span style="font-family: Arial, Helvetica, sans-serif; font-size: 13px; line-height: 13.333333015441895px; text-align: justify;">S</span><span style="font-family: Arial, Helvetica, sans-serif;"> + fall time)</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #38761d; font-family: Arial, Helvetica, sans-serif;">Answer: B</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><span style="color: #cc0000;">[15] The SCR can be turned on by</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Applying anode voltage at a sufficiently fast rate</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Applying sufficiently large anode voltage</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Increasing the temperature of SCR to a sufficiently large value</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Applying sufficiently large gate current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">OPTIONS:</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">1) A, B</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">2) C, D</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">3) B, C</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">4) A, B, C, D</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">5) None of the above options</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: 4</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<br />
<div style="text-align: left;">
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;"><b><u>Solution Hint:</u></b></span></div>
<div style="text-align: left;">
<span style="color: #0b5394; font-family: Georgia, 'Times New Roman', serif;">[2] V</span><span style="color: #0b5394; font-family: Georgia, 'Times New Roman', serif; height: 0px; line-height: 1; position: relative; text-align: justify; top: 0.5ex; vertical-align: baseline;">L</span><span style="color: #0b5394; font-family: Georgia, 'Times New Roman', serif;">= V[(Ton/(Ton+Toff)] </span></div>
<div style="text-align: left;">
<span style="color: #0b5394; font-family: Georgia, 'Times New Roman', serif;"> =V. f .Ton </span><br />
<span style="color: #0b5394; font-family: Georgia, 'Times New Roman', serif;"> There are two ways to vary </span><span style="color: #0b5394; font-family: Georgia, 'Times New Roman', serif;">V</span><span style="color: #0b5394; font-family: Georgia, 'Times New Roman', serif; height: 0px; line-height: 1; position: relative; text-align: justify; top: 0.5ex; vertical-align: baseline;">L</span><span style="color: #0b5394; font-family: Georgia, 'Times New Roman', serif;">. Either by varying f or Ton. Here f is fixed and Ton is varied. As the frequency is kept constant </span><span style="color: #0b5394; font-family: Georgia, 'Times New Roman', serif;">ripple remains constant.</span></div>
<div style="text-align: left;">
<span style="color: #0b5394; font-family: Georgia, 'Times New Roman', serif;"><br /></span></div>
<div style="text-align: left;">
<span style="color: #0b5394; font-family: Georgia, 'Times New Roman', serif;">[6] The PIV of diodes used in the full wave rectifier using two diodes is 2 times that of the four diode bridge rectifier</span></div>
<div style="text-align: left;">
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;"><br /></span></div>
<div style="text-align: left;">
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;">[7] RMS Current/ Average Current = Form Factor</span></div>
<div style="text-align: left;">
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;"><br /></span></div>
<div style="text-align: left;">
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;">[8] Idc = [Vm/2πR](1+cosα)</span></div>
<div style="text-align: left;">
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;"></span></div>
<div style="text-align: left;">
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;"> α = delay angle</span></div>
<div style="text-align: left;">
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;"><br /></span></div>
<div style="text-align: left;">
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;">[15] a= dv/dt triggering, b = forward voltage triggering, c= temperature triggering, d = gate triggering. So all are correct</span></div>
</div>
adminhttp://www.blogger.com/profile/03959820607389481053noreply@blogger.com4tag:blogger.com,1999:blog-5521862752163472752.post-9978641413104682212014-01-22T07:37:00.000-08:002014-02-11T03:23:32.916-08:00Objective Type Questions on Power Electronics: Part-11<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="font-family: Arial, Helvetica, sans-serif; font-size: small;"><u>Power Electronics Objective Type Questions with Answers: Part-11</u></span></h2>
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[1] In a SCR</span><span style="color: red; font-family: Arial, Helvetica, sans-serif;">,</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Gate current is directly proportional to forward breakover voltage</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) As gate current is raised, forward breakover voltage reduces</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Gate current has to be kept on continuously for conduction</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Forward breakover voltage is low in the forward blocking state.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: B</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[2] In a SCR, at switch on, there is a sudden increase of current, then</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) The tolerance limit of di/dt varies from 3 to 30A/us</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) di/dt upper limit is 3A/us</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) di/dt rating can be increased by having an inductive load</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) di/dt rating can be increased by a resistive load</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">Which of the above statements are true?</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(1) a, c</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(2) c, d</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(3) a, b, c, d</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(4) a, b</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: 1</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[3] The following PNPN device has a terminal for synchronising purpose</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) SUS</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) DIAC</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) TRIAC</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Schmitt trigger</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: A</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[4] In single phase full wave controlled rectifier, maximum output voltage is obtained at conduction angle....and minimum at conduction angle...</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 0°, 180°</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 180°, 0°</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) 0°, 0°</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) 180°, 180°</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: A</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[5] A thyristor is triggered by a pulse train of 5kHz. The duty ratio is 0.4. If the allowable average power is 100W the maximum allowable gate drive power is</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 100√2 W</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 50 W</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) 150 W</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) 250 W</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: D</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[6] The consequence of introducing inductance in the load circuit of SCR is</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Anode current through SCR rises slowly</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Anode current reached is more than without it</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) SCR has to be derated for anode current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) SCR's current rating can be raised</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">Which of the above statements are true?</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(1) a, c</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(2) a, b, c, d</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(3) b, d</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(4) a, d</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: 4</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[7] When a SCR is in the forward blocking state,</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) All the 3 junctions are reverse biased</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) The anode and cathode junctions are forward biased but the gate junction is reverse biased</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) The anode junction is forward biased but the cathode and gate junctions are reverse biased</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) The anode and gate junctions are forward biased but the cathode junction is reverse biased</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: B</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[8] When we need to drive a dc shunt motor at different speeds in both directions ( forward and reverse) and also to brake it in both the directions, which one of the following would you use?</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) A half-controlled SCR bridge</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) A full controlled thyristor bridge</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) A dual converter</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) A diode bridge</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: C</span></span><br />
<span style="color: #cc0000;"><span style="font-family: Arial, Helvetica, sans-serif;">[9] The frequency of the ripple present in the output voltage of the 3 phase half controlled bridge rectifier </span><span style="font-family: Arial, Helvetica, sans-serif;">depends on the</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Firing angle</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Load inductance</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Load resistance</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Supple frequency</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: D</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[10] A fully controlled thyristor bridge drives a DC motor. The system is capable of</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Motoring and braking in both directions</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Only motoring in both directions, no braking</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Motoring in forward direction and braking in reverse direction</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Only motoring in forward direction, no braking</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #38761d;">Answer: D</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="color: #cc0000;">[11] Three-phase to three-phase cycloconverter employing 18 SCRs and 36 SCRs have the same voltage and current ratings for their component thyristors. The ratio of VA rating of 36 SCR device to that of 18 SCR device is</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 1/2</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 1</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) 2</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) 4</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #274e13;">Answer: C</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="color: #cc0000;">[12] Three phase to three phase cycloconverter employing 18 SCRs are 36 SCRs have the same voltage and current ratings for their component thyristors. The ratio of power handled by 36 SCR device to that handled by 18 SCR device is</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 4</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 2</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) 1</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) 1/2</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #274e13;">Answer: A</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="color: #cc0000;">[13] The number of SCRs required for single phase to single phase cycloconverter of the mid point type and for three phase to three phase type cycloconverter are respectively</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 4, 6</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 8, 18</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) 4, 18</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) 4, 36</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #274e13;">Answer: C</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">
<span style="color: #cc0000;">[14] For dynamic equalizing circuit used for series connected SCRs, the choice of C is based on</span></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Reverse recovery characteristics</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Turn-on characteristics</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Turn-off characteristics</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Rise-time characteristics</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">OPTIONS:</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">1) A</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">2) B, C</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">3) D</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">4) A, B, C, D</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">5) None of the above options</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
<span style="color: #274e13;">Answer: 1</span></span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">[15] The function of connecting zener diode in an UJT circuit, used for the triggering of SCRs, is to</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Expedite the generation of triggering pulses</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Delay the generation of triggering pulses</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Provide a constant voltage to UJT to prevent erratic firing</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Provide a variable voltage to UJT as the source voltage changes.</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">OPTIONS:</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">1) B, C</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">2) C</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">3) A</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">4) D</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">5) None of the above options</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #38761d; font-family: Arial, Helvetica, sans-serif;">Answer: 2</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;"><b><u>Solution Hint:</u></b></span><br />
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;">[4] When the conduction angle is 0, it will not suppress any part of the input, whereas during 180 degree conduction angle, it will suppress entire input waveform.</span><br />
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;">[5] P<span style="height: 0px; line-height: 1; position: relative; text-align: justify; top: 0.5ex; vertical-align: baseline;">MAX</span> >= Pavg/(f.T<span style="height: 0px; line-height: 1; position: relative; text-align: justify; top: 0.5ex; vertical-align: baseline;">ON</span>)</span><br />
<span style="font-family: Georgia, Times New Roman, serif;"><span style="color: #0b5394;">Duty cycle D =</span><span style="color: #0b5394;">T</span><span style="color: #0b5394; height: 0px; line-height: 1; position: relative; text-align: justify; top: 0.5ex; vertical-align: baseline;">ON</span><span style="color: #0b5394;">/T = f.</span><span style="color: #0b5394;">T</span><span style="color: #0b5394; height: 0px; line-height: 1; position: relative; text-align: justify; top: 0.5ex; vertical-align: baseline;">ON</span></span><br />
<span style="font-family: Georgia, Times New Roman, serif;"><span style="color: #0b5394;">P</span><span style="color: #0b5394; height: 0px; line-height: 1; position: relative; text-align: justify; top: 0.5ex; vertical-align: baseline;">MAX</span><span style="color: #0b5394;"> >= Pavg/D =100/0.4 =250W</span></span><br />
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;">[7] When a SCR is in the forward blocking state, outer junctions (j1 & j3) are forward biased and middle junction(j2) is reverse biased</span><br />
<span style="color: #0b5394; font-family: Georgia, Times New Roman, serif;">[15] Remember that the use of zener diode in a circuit is to provide voltage regulation ( constant voltage)</span></div>
Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-5521862752163472752.post-25823167664900628802014-01-18T01:36:00.000-08:002014-02-11T03:22:52.285-08:00Power Electronics Part- 10 Objective Questions with Answers<div dir="ltr" style="text-align: left;" trbidi="on">
<h2>
<span style="color: #38761d; font-family: Arial, Helvetica, sans-serif; font-size: small;"><u>Power Electronics Objective Questions with Answers: Part-10</u></span></h2>
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">1. SCR is the solid state equivalent of</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Transistor</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Thyratron</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Vacuum diode</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Crystal diode</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: B</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">2. With gate open, if the supply voltage exceeds the breakover voltage of SCR, then SCR will conduct</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) False</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) True</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) For DC</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) For AC</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: B</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">3. The SCR is turned off when the anode current falls below</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Forward current rating</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Break over voltage</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Holding current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Latching current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: C</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">4. In a SCR circuit, the angle of conduction can be changed by changing</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Anode voltage</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Anode current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Forward current rating</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Gate current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: D</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">5. The normal way to close a SCR is by appropriate</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Gate current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Cathode current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Anode current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Forward current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: A</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">6. An SCR has ......PN junctions</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Two</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Four</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Three</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) One</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: C</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">7. If gate current is increased, the anode-cathode voltage at which SCR closes is.....</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Increased</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Decreased</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Maximum</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Least</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: B</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">8. A conducting SCR can be opened by reducing ..... to zero</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Supply voltage</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Grid voltage</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Grid current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Anode current</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: A</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">9. With gate open, a SCR can be turned-on by making supply voltage....</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Minimum</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b).Reverse</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Equal to cathode voltage</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Equal to breakover voltage</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: D</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">10. If firing angle in a SCR rectifier is increased, output is....</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Increased</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Maximum</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Decreased</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Unaffected</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: C</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">11. A SCR is a ...switch</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Two directional</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Unidirectional</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Three directional</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Four directional</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: B</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">12. The anode of SCR is always maintained at........potential with respect to cathode</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Positive</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Zero</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) negative</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) Equipotential</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: A</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">13. IF the chopper switching frequency is 200Hz and Ton time is 2ms, the duty cycle is</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) 0.4</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) 0.8</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) 0.6</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) None of the above</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: A</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">14. Speed control of induction motor can be effected by varying</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Flux</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Voltage input to stator</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Keeping rotor coil open</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) None of the above</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: B</span><br />
<span style="color: #cc0000; font-family: Arial, Helvetica, sans-serif;">15. In a Dc motor if the field coil gets opened, the speed of the motor will</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(a) Decrease</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(b) Come to stop</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(c) Increase</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">(d) None of the above</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span><span style="color: #274e13; font-family: Arial, Helvetica, sans-serif;">Answer: C</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="color: #073763; font-family: Georgia, Times New Roman, serif;"><b><u>Solution Hint:</u></b></span><br />
<span style="color: #073763; font-family: Georgia, Times New Roman, serif;">[11] SCR will conduct in one direction only. So it act as a unidirectional switch.</span><br />
<span style="color: #073763; font-family: Georgia, Times New Roman, serif;">[13] T=1/f, D = <span style="line-height: 21.81818199157715px; text-align: justify;">T</span><span style="height: 0px; line-height: 1; position: relative; text-align: justify; top: 0.5ex; vertical-align: baseline;">ON</span>/T</span></div>
Unknownnoreply@blogger.com1tag:blogger.com,1999:blog-5521862752163472752.post-41741306805536071152013-09-27T09:42:00.000-07:002014-12-07T07:42:42.409-08:00Electronics Devices Objective Type Questions: Part-6<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: justify;">
<span style="color: #274e13; font-family: Times, Times New Roman, serif; font-size: small;"><u>Electronics Devices Objective Type Questions</u></span></h2>
<div style="text-align: justify;">
<span style="color: red; font-family: Times, Times New Roman, serif;">[1] A Zener diode is used for</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">a) Voltage Regulation</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">b) Rectification</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">c) Noise Suppression</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">d) Blocking A.C</span></div>
<div style="text-align: justify;">
<span style="color: red; font-family: Times, 'Times New Roman', serif;">
</span><br />
<div id="spoiler" style="display: none;">
<span style="color: red; font-family: Times, 'Times New Roman', serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: Voltage Regulation </b></span>
</span></span></div>
<span style="color: red; font-family: Times, 'Times New Roman', serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler') .style.display=='none')
{document.getElementById('spoiler') .style.display=''}
else{document.getElementById('spoiler') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[2] An SCR is a device having</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">a) Three layers with four junctions</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">b) Three layers with two junctions</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">c) Four layers with three junctions</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">d) Two layers with three junctions</span></div>
<div style="text-align: justify;">
<span style="color: red; font-family: Times, Times New Roman, serif;">
</span><br />
<div id="spoiler1" style="display: none;">
<span style="color: red; font-family: Times, Times New Roman, serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: Four layers with three junctions </b></span>
</span></span></div>
<span style="color: red; font-family: Times, Times New Roman, serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler1') .style.display=='none')
{document.getElementById('spoiler1') .style.display=''}
else{document.getElementById('spoiler1') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[3] An amplifier has a gain of 10,000 expressed in decibels the gain is</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">a) 10</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">b) 40</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">c) 80</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">d) 100</span></div>
<div style="text-align: justify;">
<span style="color: red; font-family: Times, Times New Roman, serif;">
</span><br />
<div id="spoiler2" style="display: none;">
<span style="color: red; font-family: Times, Times New Roman, serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: 80 </b></span>
</span></span></div>
<span style="color: red; font-family: Times, Times New Roman, serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler2') .style.display=='none')
{document.getElementById('spoiler2') .style.display=''}
else{document.getElementById('spoiler2') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[4] An emitter follows has</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">a) High input impedance and high output impedance.</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">b) High input impedance and low output impedance.</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">c) Low input impedance and high output impedance.</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">d) Low input impedance and low output impedance.</span></div>
<div style="text-align: justify;">
<span style="color: red; font-family: Times, Times New Roman, serif;">
</span><br />
<div id="spoiler3" style="display: none;">
<span style="color: red; font-family: Times, Times New Roman, serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans:High input impedance and low output impedance. </b></span>
</span></span></div>
<span style="color: red; font-family: Times, Times New Roman, serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler3') .style.display=='none')
{document.getElementById('spoiler3') .style.display=''}
else{document.getElementById('spoiler3') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[5] Semi-conductor diode time constant is equal to</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">a) The value of majority carrier life time</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">b) The life time of minority carrier</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">c) The diffusion capacitance time constant</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">d) Zero</span></div>
<div style="text-align: justify;">
<span style="color: red; font-family: Times, Times New Roman, serif;">
</span><br />
<div id="spoiler4" style="display: none;">
<span style="color: red; font-family: Times, Times New Roman, serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: The value of majority carrier life time </b></span>
</span></span></div>
<span style="color: red; font-family: Times, Times New Roman, serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler4') .style.display=='none')
{document.getElementById('spoiler4') .style.display=''}
else{document.getElementById('spoiler4') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[6] To prepare a P type semiconducting material the impurities to be added to silicon are</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">a) Boron, Gallium</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">b) Arsenic, Antimony</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">c) Gallium, Phosphorous</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">d) Gallium, Arsenic</span></div>
<div style="text-align: justify;">
<span style="color: red; font-family: Times, Times New Roman, serif;">
</span><br />
<div id="spoiler5" style="display: none;">
<span style="color: red; font-family: Times, Times New Roman, serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans:Boron, Gallium </b></span>
</span></span></div>
<span style="color: red; font-family: Times, Times New Roman, serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler5') .style.display=='none')
{document.getElementById('spoiler5') .style.display=''}
else{document.getElementById('spoiler5') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[7] FET is a good signal chopper because</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">a) It exhibits no offset voltage at zero drain current</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">b) It occupies less space in integrated form</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">c) It is less noisy</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">d) It has got high input impedance</span></div>
<div style="text-align: justify;">
<span style="color: red; font-family: Times, Times New Roman, serif;">
</span><br />
<div id="spoiler6" style="display: none;">
<span style="color: red; font-family: Times, Times New Roman, serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: It exhibits no offset voltage at zero drain current </b></span>
</span></span></div>
<span style="color: red; font-family: Times, Times New Roman, serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler6') .style.display=='none')
{document.getElementById('spoiler6') .style.display=''}
else{document.getElementById('spoiler6') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[8] In Bipolar Junction transistors, the type of configuration which will give both voltage gain and current gain is</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">a) CC</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">b) CB</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">c) CE</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">d) None</span></div>
<div style="text-align: justify;">
<span style="color: red; font-family: Times, Times New Roman, serif;">
</span><br />
<div id="spoiler7" style="display: none;">
<span style="color: red; font-family: Times, Times New Roman, serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: CE </b></span>
</span></span></div>
<span style="color: red; font-family: Times, Times New Roman, serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler7') .style.display=='none')
{document.getElementById('spoiler7') .style.display=''}
else{document.getElementById('spoiler7') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[9] To increase the input resistance and decrease the output resistance in negative feedback, the type used is</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">a) Voltage Shunt</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">b) Current Series</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">c) Voltage Series</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">d) Current Shunt</span><span style="font-family: Times, 'Times New Roman', serif;"> </span></div>
<div style="text-align: justify;">
<span style="color: red; font-family: Times, Times New Roman, serif;">
</span><br />
<div id="spoiler8" style="display: none;">
<span style="color: red; font-family: Times, Times New Roman, serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: Voltage Series </b></span>
</span></span></div>
<span style="color: red; font-family: Times, Times New Roman, serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler8') .style.display=='none')
{document.getElementById('spoiler8') .style.display=''}
else{document.getElementById('spoiler8') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[10]<span class="Apple-tab-span" style="white-space: pre;"> </span>A series capacitance used in a filter circuit represents</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">a) Low-Pass</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">b) Band-Pass</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">c) High-Pass</span></div>
<div style="text-align: justify;">
<span style="font-family: Times, Times New Roman, serif;">d) None</span></div>
<div id="spoiler9" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans: High-Pass </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler9') .style.display=='none')
{document.getElementById('spoiler9') .style.display=''}
else{document.getElementById('spoiler9') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<div style="text-align: justify;">
<div style="text-align: left;">
<div style="font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 15px;">
<span style="color: red; font-family: Times, 'Times New Roman', serif;">[11] An ideal power supply is characterized by</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">a) Very large output resistance</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">b) Very small output resistance</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">c) Zero internal resistance</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">d) Infinite internal resistance</span></div>
<div>
<span style="color: red; font-family: Times, Times New Roman, serif;">
</span><br />
<div id="spoiler11" style="display: none;">
<span style="color: red; font-family: Times, Times New Roman, serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></span></div>
<span style="color: red; font-family: Times, Times New Roman, serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler11') .style.display=='none')
{document.getElementById('spoiler11') .style.display=''}
else{document.getElementById('spoiler11') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[12] An ideal diode should have</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">a) Zero resistance in the forward bias as well as reverse bias</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">b) Zero resistance in the forward bias and an infinitely large resistance in reverse bias</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">c) Infinitely large resistance in reverse bias</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">d) Infinitely large resistance in forward as well as reverse bias</span></div>
<div>
<span style="color: red; font-family: Times, Times New Roman, serif;">
</span><br />
<div id="spoiler12" style="display: none;">
<span style="color: red; font-family: Times, Times New Roman, serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: B </b></span>
</span></span></div>
<span style="color: red; font-family: Times, Times New Roman, serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler12') .style.display=='none')
{document.getElementById('spoiler12') .style.display=''}
else{document.getElementById('spoiler12') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[13] One coulomb-per-second is equal to one:</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">a) Watt</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">b) Joule</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">c) Volt</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">d) Ampere</span></div>
<div>
<span style="color: red; font-family: Times, Times New Roman, serif;">
</span><br />
<div id="spoiler13" style="display: none;">
<span style="color: red; font-family: Times, Times New Roman, serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans:D </b></span>
</span></span></div>
<span style="color: red; font-family: Times, Times New Roman, serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler13') .style.display=='none')
{document.getElementById('spoiler13') .style.display=''}
else{document.getElementById('spoiler13') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[14] Which of the following is one of the functions performed by a diode?</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">a) Filter</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">b) Amplifier</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">c) Rectifier</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">d) Inverter</span></div>
<div>
<span style="color: red; font-family: Times, Times New Roman, serif;">
</span><br />
<div id="spoiler14" style="display: none;">
<span style="color: red; font-family: Times, Times New Roman, serif;"><span style="text-align: left;"><span style="color: green;"><b>Ans: C </b></span>
</span></span></div>
<span style="color: red; font-family: Times, Times New Roman, serif;"> <span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler14') .style.display=='none')
{document.getElementById('spoiler14') .style.display=''}
else{document.getElementById('spoiler14') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
[15] What is the “power factor”?</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">a) Ratio of true power to apparent power</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">b) Peak power times 0.707</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">c) Sin of the phase difference between E and I</span></div>
<div>
<span style="font-family: Times, Times New Roman, serif;">d) Cos of the phase angle between true power and apparent power</span></div>
<div id="spoiler15" style="display: none;">
<span style="text-align: left;"><span style="color: green;"><b>Ans:A </b></span>
</span></div>
<span style="text-align: left;">
<button onclick="if(document.getElementById('spoiler15') .style.display=='none')
{document.getElementById('spoiler15') .style.display=''}
else{document.getElementById('spoiler15') .style.display='none'}
" style="background-color: lightgreen;" title="Click to Answer content" type="button">Answer</button> </span> <br />
<div>
<div style="font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 15px;">
<span style="font-family: 'Courier New', Courier, monospace;"><b style="color: blue; text-align: justify;"><br /></b></span></div>
<div style="text-align: justify;">
<b><u><span style="color: #0b5394; font-family: Trebuchet MS, sans-serif;">Solution Hint:</span></u></b></div>
<div style="text-align: justify;">
<span style="color: #0b5394; font-family: Trebuchet MS, sans-serif;">[1] General purpose diode is used for rectification, whereas zener diode is for voltage regulation<br />[3] Power gain = 10000 <br />Gain in dB = 10log(10000) = 40dB <br />Voltage gain = 10000 <br />Gain in dB = 20log(10000) = 80dB </span></div>
<div style="text-align: justify;">
<span style="color: #0b5394;"><span style="font-family: Trebuchet MS, sans-serif;">[4] In the Emitter follower circuit, the input side (base-collector terminals) is reverse biased, ie, High input impedance and the </span><span style="font-family: 'Trebuchet MS', sans-serif;">Output side (emitter-collector terminals) is forward biased ie, low output impedance</span></span></div>
<div style="text-align: justify;">
<span style="color: #0b5394; font-family: Trebuchet MS, sans-serif;">[11] Ideal power supply should not dissipate heat ( ie, internal resistance should be near to zero)</span></div>
<div style="text-align: justify;">
<span style="color: #0b5394; font-family: Trebuchet MS, sans-serif;">[12] Ideal diode is nothing but ideal DC switch( zero resistance while turned-on and infinity resistance while turned-off)</span></div>
<div style="text-align: justify;">
<span style="color: #0b5394; font-family: Trebuchet MS, sans-serif;">[13] Flow of charges (unit = coulomb) is known as current(unit = ampere).<b> </b></span></div>
</div>
</div>
</div>
</div>
adminhttp://www.blogger.com/profile/03959820607389481053noreply@blogger.com5