# Analog Electronics MCQ Questions & Answers

Analog Electronics MCQs : This section focuses on the "Analog Electronics". These Multiple Choice Questions (MCQs) should be practiced to improve the Analog Electronics skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.

Question 1

A bridge rectifier circuit has input of 50 Hz frequency. The load resistance is RL and filter capacitance is C. For good output wave shape, the time constant RLC should be at least equal to

A. 10 ms
B. 20 ms
C. 50 ms
D. 100 ms

Question 2

A CB amplifier has re = 6 Ω, RL = 600 Ω and a = 0.98. The voltage gain is

A. 100
B. 600 x 0.98
C. 98
D. 6

Question 3

A forward voltage of 9 V is applied to a diode in series with a 1 kΩ load resistor. The voltage across load resistor is zero. It indicates that

A. diode is short circuited
B. diode is open circuited
C. resistor is open circuited
D. diode is either short circuited or open circuited

Question 4

A half wave diode circuit using ideal diode has an input voltage 20 sin ωt volts. Then average and rms values of output voltage are

A. and 10 V
B. and 10 V
C. and 5 V
D. and 5 V

Question 5

A half wave diode rectifier has a capacitance input filter. If input voltage is Vm sin ωt, PIV is

A. Vm
B. 2 Vm
C. 3 Vm
D. 4 Vm

Question 6

An amplifier has a large ac input signal. The clipping occurs on both the peaks. The output voltage will be nearly a

A. sine wave
B. square wave
C. triangular wave
D. (a) or (c)

Question 7

An amplifier with loop gain Aβ will be more stable for value of Aβ as

A. 0.95
B. 0.7
C. 1.2
D. 1.5

Question 8

An exponential amplifier has diode in feedback path.

A. TRUE
B. FALSE

Question 9

An RC coupled amplifier has an open loop gain of 200 and a lower cutoff frequency of 50 Hz. If negative feedback with β = 0.1 is used, the lower cut off frequency will be

Question 10

Assertion (A): CE amplifier is the most widely used BJT amplifierReason (R): CE amplifier has zero phase difference between input and output

A. Both A and R are correct and R is correct explanation for A
B. Both A and R are correct but R is not correct explanation for A
C. A is correct R is wrong
D. A is wrong R is correct

Question 11

Assertion (A): For large signal variations an amplifier circuit has to be analysed graphicallyReason (R): The output characteristics of a transistor is nonlinear.

A. Both A and R are correct and R is correct explanation for A
B. Both A and R are correct but R is not correct explanation for A
C. A is correct R is wrong
D. A is wrong R is correct

Question 12

Consider the following statements : A clamper circuit adds or subtracts a dc voltage to a waveformdoes not change the waveformamplifiers the waveform Which are correct?

A. 1, 2
B. 1, 3
C. 1, 2, 3
D. 2, 3

Question 13

DC amplifiers have a tendency to be unstable.

A. TRUE
B. FALSE

Question 14

For a base current of 10 μA, what is the value of collector current in common emitter if βdc = 100

A. 10 μA
B. 100 μA
C. 1 mA
D. 10 mA

Question 15

If an amplifier with gain of - 1000 and feedback factor β = - 0.1 had a gain change of 20% due to temperature, the change in gain of the feedback amplifier would be

A. 10%
B. 5%
C. 0.20%
D. 0.01%

Question 16

In a BJT circuit a pnp transistor is replaced by npn transistor. To analyse the new circuit

A. all calculations done earlier have to be repeated
B. replace all calculated voltages by reverse values
C. replace all calculated currents by reverse values
D. replace all calculated voltages and currents by reverse values

Question 17

In a CE amplifier the input impedance is equal to the ratio of

A. ac base voltage to ac base current
B. ac base voltage to ac emitter current
C. ac emitter voltage to ac collector current
D. ac collector voltage to ac collector current

Question 18

In class C operation of an amplifier circuit, the collector current exists for

A. 360° of input wave
B. 180° of input wave
C. more than 180° of input wave
D. less than 180° of input wave

Question 19

Maximum efficiency of class B power amplifier is 50%.

A. TRUE
B. FALSE

Question 20

Negative feedback reduces noise originating at the amplifier input.

A. TRUE
B. FALSE

Question 21

The efficiency of a full wave rectifier using centre tapped transformer is twice that in full wave bridge rectifier.

A. TRUE
B. FALSE

Question 22

The load impedance ZL of a CE amplifier has R and L in series. The phase difference between output and input will be

A. 180°
B. 0
C. more than 90° but less than 180°
D. more than 180° but less than 270°

Question 23

The quiescent collector current IC, and collector to emitter voltage VCE in a CE connection are the values when

A. ac signal is zero
B. ac signal is low
C. ac signal is negative
D. either (a) or (b)

Question 24

The self bias provides

A. stable Q point
B. large voltage gain
C. high input impedance
D. high base current

Question 25

To prevent a DC return between source and load, it is necessary to use

A. resistor between source and load
B. inductor between source and load
C. capacitor between source and load
D. either (a) or (b)

Question 26

To protect the diodes in a rectifier and capacitor input filter circuit it is necessary to use

A. surge resistor
B. surge inductor
C. surge capacitor
D. both (a) and (b)

Question 27

Which of the following oscillators is suitable for frequencies in the range of mega hertz?

A. RC phase shift
B. Wien bridge
C. Hartley
D. Both (a) and (c)