Explore topic-wise MCQs in Testing Subject.

This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.

1.

A Darlington pair consist of

A. two CB amplifiers
B. two CC amplifiers
C. two cascaded CC amplifiers
D. two cascaded CE amplifiers
Answer» D. two cascaded CE amplifiers
2.

The most common method for biasing a JFET is

A. reverse bias
B. self bias
C. voltage divider bias
D. none of the above
Answer» C. voltage divider bias
3.

A Darlington pair is used for

A. low distortion
B. high frequency range
C. high power gain
D. high current gain
Answer» E.
4.

In a class C operation

A. VCC is much larger than VCE(sat)
B. VCC is much smaller than VCE(sat)
C. VCC and VCE(sat) are nearly equal
D. none of the above
Answer» B. VCC is much smaller than VCE(sat)
5.

In a series regulated power supply circuit, the voltage gain Av, of the 'pass' transistor satisfies the condition

A. Av ‚Üí ‚àû
B. 1 << Av < ‚àû
C. Av ≈ 1
D. Av << 1
Answer» D. Av << 1
6.

A half wave diode rectifier uses a diode having forward resistance of 50 ohms. The load resistance is also 50 ohms. Then the voltage regulation is

A. 0.2
B. 0.5
C. 1
D. 2
Answer» D. 2
7.

Whenever a JFET operates above pinch-off voltage

A. depletion regions become smaller
B. drain current increase steeply
C. drain current starts decreasing
D. drain current remains nearly constant
Answer» E.
8.

Positive feedback is mainly used in

A. oscillators
B. thyristors
C. voltage regulators
D. both (a) and (b)
Answer» E.
9.

The basic amplifier in Weinbridge oscillator consists of

A. CE stage followed by CE
B. CE stage followed by CB
C. CB stage followed by CE
D. CC stage followed by CE
Answer» B. CE stage followed by CB
10.

In a CE amplifier circuit

A. Q point must lie on both dc and ac load lines
B. Q point lies on dc load line
C. Q point lies on ac load line
D. Q point lies may or may not lie on both dc and ac load lines
Answer» B. Q point lies on dc load line
11.

The signal input to a given amplifier is made up of 100 mΩ signal power and 1 mΩ noise power. The amplifier contributes an additional 100 mΩ of noise and has a power gain of 20 dB. The output signal-to-noise ratio is

A. 100
B. 50
C. 10
D. 5
Answer» C. 10
12.

A cascade amplifier stage is equivalent to

A. common emitter stage followed by a common base stage
B. common base stage followed by an emitter follower
C. an emitter follower stage followed by a common base stage
D. a common base stage followed by a common emitter stage
Answer» B. common base stage followed by an emitter follower
13.

In figure the dc load line will meet the y and x axis respectively at

A. 20 mA and 30 V
B. 15 mA and 20 V
C. 25 mA and 40 V
D. 10 mA and 20 V
Answer» B. 15 mA and 20 V
14.

An op-amp integrating circuit uses

A. an inductor
B. a capacitor
C. both inductor and capacitor
D. none of the above
Answer» C. both inductor and capacitor
15.

An ideal op-amp has

A. infinite input and output resistance
B. low input and output resistance
C. low input and high output resistance
D. infinite input resistance and zero output resistance
Answer» E.
16.

In figure, IC ≈

A. I1
B. IB
C. 0.5 I1
D. 0.5 IB
Answer» B. IB
17.

For the circuit shown in figure low cut-off frequency is

A. 1.59 Hz
B. 159 Hz
C. 1.59 kHz
D. 1.59 MHz
Answer» B. 159 Hz
18.

The zener diode in the rectangular circuit shown in the figure has a zener voltage of 5.8 volts and a zener knee current of 0.5 mA. The maximum load current drawn from this circuit ensuring proper functioning over the input voltage range between 20 and 30 volts, is

A. 23.7 mA
B. 14.2 mA
C. 13.7 mA
D. 24.2 mA
Answer» E.
19.

A Wien bridge is suitable for

A. audio frequencies only
B. radio frequencies only
C. both audio and radio frequencies
D. very low frequencies only
Answer» B. radio frequencies only
20.

The purpose of providing groundings rings with MOSFET is to

A. avoid any stray voltage at the gate that may destroy SiO2 layer
B. protect against any descaling
C. ground all eddy currents
D. protect against any physical injury
Answer» B. protect against any descaling
21.

A multivibrator generates

A. sinusoidal waveforms
B. non-sinusoidal waveforms
C. both (a) and (b)
D. none of the above
Answer» B. non-sinusoidal waveforms
22.

Find resistance RB to bring transistor to threshold of saturation VCB = 0, VBE = 0.7 V, a = 0.96

A. 1.5 kΩ
B. 15 kΩ
C. 10 kΩ
D. 1 kΩ
Answer» B. 15 kŒ©
23.

The leakage current in CB configuration may be around

A. few micro amperes
B. few hundred micro amperes
C. few milliamperes
D. few hundred milliamperes
Answer» B. few hundred micro amperes
24.

The slew rate of an ideal op-amp is

A. very slow
B. slow
C. fast
D. infinitely fast
Answer» E.
25.

Class A amplifiers are preferred when

A. minimum distortion is required
B. maximum voltage gain is required
C. output signal is desired in phase with input signal
D. signal having A.C. superimposed on D.C. are to be amplified
Answer» B. maximum voltage gain is required
26.

A 741 type op-amp has a gain bandwidth product of 1 MHz. A non-inverting amplifier using this op-amp and having a voltage gain of 20 dB will exhibit a -3dB bandwidth of

A. 50 kHz
B. 100 kHz
Answer» C.
27.

As compared to full wave rectifier, a half wave rectifier

A. has higher ripple factor
B. has lower ripple factor
C. may have higher or lower ripple factor
D. has same ripple factor
Answer» B. has lower ripple factor
28.

The ideal characteristics of a stabilizer is

A. constant output voltage with low internal resistance
B. constant output current with low internal resistance
C. constant output voltage with high internal resistance
D. constant internal resistance and constant output current
Answer» B. constant output current with low internal resistance
29.

The bandwidth of an amplifier can be reduced by

A. miller effect compensation
B. pole zero compensation
C. dominant pole compensation
D. lead compensation
Answer» D. lead compensation
30.

In a P-N-P transistor, electrons flow

A. into the transistor at the collector only
B. into the transistor at the base and the collector leads
C. out of the transistor at base and collector leads
D. out of the transistor at base, collector as well as emitter leads
Answer» C. out of the transistor at base and collector leads
31.

Which circuit is called emitter follower?

A. CC
B. CE
C. CB
D. Both (a) and (b)
Answer» B. CE
32.

Emitter follower is in which of following configuration.

A. common Base
B. common Emitter
C. common collector
D. common Base or common Emitter
Answer» D. common Base or common Emitter
33.

In the amplifier circuit figure the quiescent point voltage and current are

A. 12 V, 5 mA
B. 12 V, 2 mA
C. 10 V, 2 mA
D. 10 V, 5 mA
Answer» D. 10 V, 5 mA
34.

The circuit consisting of two transistor connected in series with the d.c. supply voltage is called

A. push pull
B. differential pair
C. stacked V+
D. complementary symmetry
Answer» D. complementary symmetry
35.

Assertion (A): As per Miller theorem a capacitance C from input to output appears as a much larger capacitance across input terminalsReason (R): In a lag network the output voltage appears across capacitor

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
Answer» C. A is correct R is wrong
36.

As per miller theorem the circuit of figure (1) can be replaced by that in figure (2) If V1/V2 = K, then Y1 and Y2 are equal to

A. Y(1 - K) each
B. each
C. Y1 = Y(1 - K) and Y2 =
D. Y1 = and Y2 = (1 - K)
Answer» D. Y1 = and Y2 = (1 - K)
37.

In CE approximation, the upper end of d.c. load line is called the __________ point and the lower end is the __________ point.

A. Q, base
B. base, Q
C. saturation, cut off
D. cut off, saturation
Answer» D. cut off, saturation
38.

Calculate the O/P voltage of a non-inverting constant gain multiplier with R1 = 100 kΩ, Rf= 600 kΩ, V1 = 2 volt, then O/P voltage Vo of non inverting op-amp is given by

A. 16 V
B. 14 V
C. 20 V
D. 15 V
Answer» C. 20 V
39.

A bipolar transistor is a __________ controlled devices whereas a FET is a __________ controlled devices.

A. current, voltage
B. current, current
C. voltage, current
D. voltage, voltage
Answer» B. current, current
40.

In figure VCE (sat) = 0.1 V. Then IC (sat) =

A. 10 mA
B. 20 mA
C. 30 mA
D. 40 mA
Answer» C. 30 mA
41.

In a differential amplifier, CMRR can be improved by using an increased

A. emitter resistance
B. collector resistance
C. power supply voltages
D. source resistance
Answer» B. collector resistance
42.

Assertion (A): If we overdrive an amplifier the output signal may get clippedReason (R): To dissipate heat to atmosphere a heat sink is sometimes attached to the case of transistor

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
Answer» C. A is correct R is wrong
43.

In every practical oscillator, the loop gain is slightly larger than unity and the amplitude of the oscillations is limited by the

A. magnitude of the loop gain
B. onset if non-linearity
C. magnitude of gain of the amplifier
D. feedback transmission factor
Answer» C. magnitude of gain of the amplifier
44.

Drain feedback bias is often used with

A. D MOSFETs
B. E MOSFETs
C. both D and E MOSFETs
D. neither D nor E MOSFETs
Answer» C. both D and E MOSFETs
45.

For input and later stages, BI-FET op-amp use

A. JFETs and MOSFETs respectively
B. MOSFETs and JFETs respectively
C. JFETs and BJTs respectively
D. BJTs and JFETs respectively
Answer» D. BJTs and JFETs respectively
46.

Oscillator with best frequency stability is

A. Crystal oscillator
B. Phase shift oscillator
C. Clapp oscillator
D. Hartley oscillator
Answer» B. Phase shift oscillator
47.

In a common emitter circuit all voltages are measured with respect to

A. base
B. emitter
C. collector
D. base or collector
Answer» C. collector
48.

The re model equivalent circuit shown in figure is for

A. CE amplifier
B. CC amplifier
C. CB amplifier
D. None of the above
Answer» D. None of the above
49.

The circuit shown in figure will act as

A. differentiator
B. adder
C. clipper
D. clamper
Answer» D. clamper
50.

For a transistor if adc = 0.98 and emitter current IE is 2 mA, then collector current will be

A. 0.44 mA
B. 0.88 mA
C. 1.96 mA
D. 3.32 mA
Answer» C. 1.96 mA