Saturday, October 27, 2012

Instrumentation Part-1 Objective Questions

Solved Objective Questions from Measurements & Instrumentation:

[1] The major advantage of electromagnet type meter over a permanent magnet meter is
A.  The electromagnet meter costs much less
B.  The permanent magnet meter has a more sluggish coil
C.  The electromagnet meter need not be aligned with the earth’s magnetic field
D.  The electromagnet meter is more rugged

[2] A thermocouple
A.  Gets warm when dc flows through it
B.  Is a thin, straight, special wire
C.  Generates ac when heated
D.  Generates dc when exposed to visible light

[3] If the readings of the two watt meters in the 2 watt meter method of power measurement are 4.5 kW and 3.5 kW respectively and the latter reading has been obtained after reversing the current coil of the watt meter. What will be the total power in kW?
A.  1
B.  3.5
C.  4.5
D.  8

[4]The major advantage of an electrostatic meter is
A.  It can handle large currents
B.  It measures very small currents
C.  It can detect and indicate ac voltages as well as dc voltages
D.  It draws a large current from a power supply.

[5] The change in the direction of a compass needle, when a current carrying wire is brought near, is called
A.  Electromagnetic deflection
B.  Electroscopic force
C.  Magnetic force
D.  Electrostatic force

[6] Ammeter shunts are useful because
A.  They prevent overheating of the meter movement
B.  They make a meter more physically rugged
C.  They allow for measurement of large currents
D.  They increase meter sensitivity

[7] Suppose a certain current in a galvanometer causes the compass needle to deflect by 20 degree, then this current is doubled while the polarity stays the same. The angle of the needle deflection will
A.  Reverse direction
B.  Stay the same
C.  Increase
D.  Decrease

[8] The major advantage of FETVM over a conventional voltmeter is that FETVM
A.  Can withstand higher voltages safely
B.  Draws less current from the circuit under test
C.  Can measure lower voltages
D.  Is sensitive to ac voltage as well as to dc voltage

[9] The attraction or repulsion between two electrically charged objects is called
A. Electromagnetic deflection
B. Electrostatic force
C. Electroscopic force
D. Magnetic force

[10] A utility meter’s reading indicates
A. Current
B. Power
C. Voltage
D. Energy

[11] When a signal of 10 mV at 75 MHz is to be measured then which of the following instrument can be used -
a) VTVM
b) Cathode ray oscilloscope
c) Moving iron voltmeter
d) Digital multimeter


[12] The most useful transducer for displacement sensing with excellent sensitivity, linearity and resolution is?
a) An incremental encoder
b) An absolute encoder
c) LVDT
d) A strain gauge


[13] When variable reluctance type tachometer has 150 teeth on the rotor & the counter records 13,500 pulses per second then the rotational speed will be?
a) 4800 rpm
b) 5400 rpm
c) 6000 rpm
d) 7200 rpm.


[14] One of the following, which is not a transducer in the true sense, is ?
a) Thermocouple
b) Piezoelectric pick up
c) Photo-Voltaic cell
d) LCD


[15] Choose the correct statement
(a) Digital multimeters are built using current measuring elements, while analog multimeters are built using voltage measuring units
(b) Digital multimeters are built using voltage measuring units, while analog multimeters are built using current measuring units
(c) Both digital and analog multimeters are built using voltage measuring units
(d) Both digital and analog multimeters are built using current measuring units




5:29 AM

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