Wednesday, October 17, 2012

Electronic Devices, Amplifiers Solved Objectives: Part-1

Electronic Devices Objective Questions:

[1] The action of JFET in its equivalent circuit can be represented as a
A. Current controlled Current source
B. Current controlled Voltage source
C. Voltage controlled Voltage source
D. Voltage controlled Current source

[2] A change in the value of the emitter resistance Re in a differential amplifier
A. Affects the difference mode gain Ad
B. Affects the common mode gain Ac
C. Affects both Ad and Ac
D. Does not effect either Ad and Ac

[3] Generally, the gain of a transistor amplifier falls at high frequencies due to the
A. Internal Capacitance of the device
B. Coupling capacitor at the input
C. Skin effect
D. Coupling capacitor at the output

[4] In a common emitter, unbypassed resistor provides
A. Voltage shut feedback
B. Current series feedback
C. Negative voltage feedback
D. Positive current feedback

[5] A constant current signal across a parallel RLC circuits gives an o/p of 1.4V at the signal frequency of 3.89kHz. At the frequency of 4 kHz, the o/p voltage will be
A. 1 V
B. 2 V
C. 1.4 V
D. 2.8 V

[6] Class AB operation is often used in power (large signal) amplifiers in order to
A. Get maximum effeciency
B. Remove even harmonics
C. Overcome a crossover distortion
D. Reducing collector dissipation

[7] The bandwidth of an RF tuned amplifier is dependent on
A. Q-factor of the tuned O/P circuit
B. Q-factor of the tuned I/P circuit
C. Quiescent operating point
D. Q-factor of the O/P and I/P circuits as well as quiescent operating point

[8]Most of the linear ICs are based on the two-transistor differential amplifier because of its
A. Input voltage dependent linear transfer characteristics
B. High voltage gain
C. High input resistance
D. High CMMR

[9] Negative feedback in an amplifier
A. Reduces gain
B. Increase frequency and phase distortion
C. Reduces bandwidth
D. Increase Noise

10] A dc power supply has no-load voltage of 30V and a full-load voltage of 25V at full-load current of 1A. Its output resistance and load regulation respectively are
A. 5Ω & 20%
B. 25Ω & 20%
C. 5Ω &16.7%
D. 25Ω & 16.7%
6:39 PM


  1. load regulation .. No load voltage - full load voltage )/ No load voltage *100....... (30-25)/30 *100/1

    1. load regulation is (no load voltage-full load voltage)/ full load voltage*100