ies - electronics engineering - analog electronic circuits

IES E & T Topic wise QuestionsAnalog Electronic Circuits

www.gatehelp.com

YEAR 1999

MCQ 1

Assertion(A): A monostable multivibrator can be used to alter the pulse width a repetitive pulse train.

Reason (R): Monostable multivibrator has a single stable state.

(A) Both A and R are true and R is the correct explanation of A

(B) Both A and R are true but R is NOT the correct explanation of A

(C) A is true but R is false

(D) A is false but R is true

MCQ 2

Assertion (A): Miller sweep circuit producing sawtooth waveform is a relaxation oscillator.

Reason (R): The active device alternately supplies power to the load and relaxes when it is cut off.





IES E & T Topic wise 1999-2009 Analog Electronic Circuits

www.gatehelp.com

MCQ 3

Assertion (A): In the circuit shown in the figure, above a prescribed value of load current IL , V0 will gradually fall.

Reason (R): A above the prescribed value, as load current IL increases, IB decreases.





MCQ 4

Assertion (A): A large negative feedback is deliberately introduced in an amplifier to make its gain independent of the variation of parameters of the active device and other circuit components.

Reason (R): A large negative feedback results in a high value of return difference compared to unity, which makes the feedback gain inversely proportional to the feedback factor.





MCQ 5

The given figure shows a composite transistor consisting of a MOSFET

IES E & T Topicwise 1999-2009Analog Electronic Circuits

www.gatehelp.com

and a bipolar transistor in cascode

The MOSFET has a trans-conductance gm of 2 /mA V and the bipolar

transistor has hfeβ Δ_ i of 99. The overall transconductance of the

composite transistor is

(A) 198 mA/V (B) 19.8 mA/V

(C) 1.98 A/V (D) 1.98 mA/V

MCQ 6

In a single-stage differential amplifier, the output offset voltage is

basically dependent on the mismatch of

(A) ,V IBE B and β (B) VBE and IB

(C) IB and β (D) VBE and β

MCQ 7

The input resistance of a common emitter stage can be increased by

1. unbypassing emitter resistance

2. bootstrapping

3. biasing it at low quiescent current

4. using compounded BJTs

The correct sequence in descending order of the effectiveness of these

methods is

(A) 2, 4, 1, 3 (B) 4, 3, 2, 1

(C) 2, 4, 3, 1 (D) 4, 2, 3, 1


www.gatehelp.com

MCQ 8

The collector voltage VC of the circuit shown in the given figure is approximately

(A) 2 V (B) 4.6 V

(C) 8 V (D) 8.6 V

MCQ 9

Thermal runaway will take place if the quiescent point is such that

(A) V V21>CE CC (B) V V<CE CC

(C) V V2<CE CC (D) V V21<CE CC

MCQ 10

Circuit shown in the given figure represents

(A) an astable multivibrator

(B) a monostable multivibrator

(C) voltage controlled oscillator

(D) ramp generator


www.gatehelp.com

MCQ 11

In a feedback series regulation circuit, the output voltage is regulated by controlling the

(A) magnitude of the input voltage

(B) gain of the feedback transistor

(C) reference voltage

(D) voltage drop across the series pass transistor

MCQ 12

A three-terminal monolithic IC regulator can be used as

(A) an adjustable output voltage regulator alone

(B) an adjustable output voltage regulator and a current regulator

(C) a current regulator and a power switch

(D) a current regulator alone

MCQ 13

Which one of the following devices is NOT used as the controller in a stabilizer?

(A) Diac (B) Triac

(C) SCR (D) Power transistor

MCQ 14

A second-order band-pass active filter can be obtained by cascading a low-pass second-order section having cut-off frequency fOH with a high-pass second-order section having cut-off frequency fOL, provided

(A) f f>OH OL (B) f f<OH OL

(C) f fOH OL= (D) f f21

OH OL#

MCQ 15

If a class C power amplifier has an input signal with frequency of 200 kHz and the width of collector current pulses of 0.1 sμ , then the duty cycle of the amplifier will be

(A) 1% (B) 2%

(C) 10% (D) 20%


www.gatehelp.com

MCQ 16

The given circuit has a feedback factor of

(A) /R RC S− (B) /R RE C−

(C) /R RE S− (D) /R RC E−

MCQ 17

A Hartley oscillator is used for generating

(A) very low frequency oscillation

(B) radio-frequency oscillation

(C) microwave oscillation

(D) audio-frequency oscillation

MCQ 18

The output voltage V0 of the given circuit

(A) 100 V− (B) 100 mV−

(C) 10 V (D) 10 mV−


www.gatehelp.com

MCQ 19

The voltage gain versus frequency curve of an Op-Amp is shown in

the given figure

The gain-bandwidth product of the Op-Amp is

(A) 200 Hz (B) 200 MHz

(C) 200 kHz (D) 2 MHz

MCQ 20

The v0 of the Op-Amp circuit shown in the given figure is

(A) v11 1 (B) v10 1

(C) v1 (D) zero

MCQ 21

A 12 V monolithic regulator is adjusted to obtain a higher output

voltage as shown in the given figure


www.gatehelp.com

The v0 will be

(A) 12 V (B) 17 V

(C) 24 V (D) 29 V

MCQ 22

The voltage V0 of the circuit shown in the given figure is

(A) 5 V (B) 3.1 V

(C) 2.5 V (D) zero

YEAR 2000

MCQ 23

Assertion (A): Op-amps with FET input stages have less gain than those with BJT.

Reason (R): BJT has higher transconductance than FET.






www.gatehelp.com

MCQ 24

Assertion (A): For equal outputs, the harmonic distortion is reduced in CE amplifier with the introduction negative feedback.

Reason (R): Nonlinear distortion usually arises due to signals traversing the large part of the dynamic characteristic of the transistor at the output stage.



(C) A is true and R is false


MCQ 25

Assertion (A): Thyristors are preferred over power diodes in variable power rectifiers.

Reason (R): Thyristors provide controlled rectification even though they have more power loss in comparison to power diodes.





MCQ 26

A common emitter amplifier circuit is shown in the given figure

The slope of AC load line is

(A) R R1 1

L C− +b l (B) R R

1L C

− +b l


www.gatehelp.com

(C) R1

L− (D) R

1C

−

MCQ 27

An amplifier circuit is shown in the given figure:

The voltage gain ( / )V Vs0 is(A) 4/3.33 (B) 100

(C) 150 (D) 160

MCQ 28

Consider the following statements:

A totem pole configuration used is the output state of an op-amp has the advantage of using

1. only n-p-n BJTs

2. complementary symmetrical pair of transistors.

3. only one transistor

Which of these statement is/are correct?(A) 1 alone (B) 2 alone

(C) 3 alone (D) 1 and 3

MCQ 29

A 1 ms pulse can be stretched to 1 s pulse by using

(A) an astable multivibrator

(B) a monostable multivibrator

(C) a bistable multivibrator

(D) a Schmitt trigger circuit


www.gatehelp.com

MCQ 30

An FET is a better chopper than a BJT because it has

(A) lower offset voltage

(B) higher series ON resistance

(C) lower input current

(D) higher input impedance

MCQ 31

Consider the following statements regarding the bootstrap biasing

arrangement for a BJT emitter follower:

1. The input impedance is very high.

2. The voltage gain is exactly equal to one.

3. The output impedance is equal to zero.

Which of these statements is correct?

(A) None (B) 2 alone

(C) 3 alone (D) 1 alone

MCQ 32

In the circuit shown in the given figure, the approximate voltages at

the transistor

(A) base and emitter respectively are 8 V− and 7.3 V−

(B) base and collector respectively are 8 V− and 5 V−

(C) collector and emitter respectively are 8 V− and 7.3 V−

(D) base, emitter and collector respectively are 8 V− , 7.3 V− and

5 V−


www.gatehelp.com

MCQ 33


The lower cut-off frequencies for an RC coupled CE amplifier depend on

1. input and output coupling capacitors

2. emitter bypass capacitor

3. junction capacitors

Which of these statements is/are correct?(A) 1 alone (B) 2 alone

(C) 1 and 2 (D) 2 and 3

MCQ 34

The op-amp circuit shown in the given figure is

(A) a high-pass circuit (B) a low-pass circuit

(C) a band pass circuit (D) an all-pass circuit

MCQ 35

Consider the following statements: Sziklai pair

1. is also called complementary Darlington.

2. acts like a single p-n-p transistor with a very high current gain.

3. can be used in class B push-pull power amplifier.

Which of these statements are correct?(A) 1 and 2 (B) 1 and 3

(C) 2 and 3 (D) 1, 2 and 3

MCQ 36

Which one of the following power amplifiers has the maximum


www.gatehelp.com

efficiency?

(A) Class A (B) Class B

(C) Class AB (D) Class C

MCQ 37

If a common emitter amplifier with an emitter resistance Re has an overall transconductance gain of 1 /mA V− , a voltage gain of 4− and desensitivity of 50, then the value of the emitter resistance Re would be

(A) 50 kΩ (B) 0.98 kΩ

(C) 50 kΩ (D) 0.98 kΩ

MCQ 38

The voltage gain of an amplifier without feedback respectively are 100 and 20. The percentage of negative feedback ( )β would be

(A) 4% (B) 5%

(C) 20% (D) 80%

MCQ 39

If the Q of a single-stage single-turned amplifier is doubled, then its bandwidth will

(A) remain same (B) become half

(C) become double (D) become four times

MCQ 40

An amplifier using BJT has two identical stages each having a lower cut-off (3 dB) frequency of 64 Hz due to coupling capacitor. The emitter bypass capacitor also provides a lower cut-off (3 dB) frequency due to emitter degeneration alone of 64 Hz. The lower of (3 dB) frequency of the overall amplifier is nearly

(A) 100 Hz (B) 128 Hz

(C) 156 Hz (D) 244 Hz

MCQ 41

Consider the following statements in relation to a large value of capacitor filter used in a full-wave rectifier:


www.gatehelp.com

It gives the1. low conduction period for the diode rectifier.

2. increased peak current rating of the diode.

3. large peak inverse voltage rating of the diode.

Which of these statements are correct?(A) 1, 2 and 3 (B) 2 and 3

(C) 1 and 2 (D) 1 and 3

MCQ 42

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 of non-linearity

(C) magnitude of the gain of the amplifier

(D) feedback transmission factor

MCQ 43

In the circuit shown in the given figure, the current flowing through resistance of 100 Ω would be

(A) 8 mA (B) 10 mA

(C) 20 mA (D) 100 mA

MCQ 44

Which one of the following sets of circuits can be obtained by using a 555 timer?


www.gatehelp.com

(A) Pulse modulator and amplitude demodulator

(B) Pulse modulator and astable multivibrator

(C) Amplitude demodulator and AC to DC converter

(D) AC to DC converter and astable multivibrator

MCQ 45

The input voltage of Zener regulator varies from 20 V to 30 V. The

load current varies from 10 mA to 15 mA. If the Zener voltage is 5 V

, the value of series resistor will be

(A) 1 kΩ (B) 1.5 kΩ

(C) 1.66 kΩ (D) 2.5 kΩ

MCQ 46

CE configuration is the most preferred transistor configuration when

used as a switch because it

(A) requires only one power supply

(B) requires low voltage or current

(C) is easily understood by every one

(D) has small ICEO

MCQ 47

The thermal run-away in a CE transistor amplifier can be prevented

by biasing the transistor in such a manner that

(A) V V2>CECC (B) V V

2<CECC

(C) V V2CECC= (D) V 0CE =

YEAR 2001

MCQ 48

In the circuit shown in the given figure, V0 is given by


www.gatehelp.com

(A) ( / )sin t 4π− (B) ( / )sin t 4π+

(C) sin t (D) cos t

MCQ 49

Assertion (A): In an op-amp circuit when one input terminal of the op-amp is grounded, the other terminal becomes a virtual ground.

Reason (R): Input impedance of the op-amp is high.




(D) A is false but R is false

MCQ 50

Assertion (A): While using UJT for the generation of saw-tooth voltage, it has to be biased so that it can work within the range of V-I characteristic.

Reason (R): Within a range of its V-I characteristic, the UJT has negative resistance and can be used as an oscillator.





MCQ 51

Assertion (A): In an amplifier with negative feedback, the gain-stability is improved by the factor A1 β+ where A is the magnitude


www.gatehelp.com

of gain and β is the feedback factor.

Reason (R): The relation between gain with feedback Af and gain

without feedback A,

is A AA

1f β= + . Thus AdA

A AdA

11

f

f

β= +


(B) Both A and R are true but R is NOT the correct explanation of

A



MCQ 52

Assertion (A): Two stage stagger-tuned amplifier should have greater

bandwidth and flatter pass band.

Reason (R): When synchronous tuning is used in two cascaded tuned

circuits, the bandwidth reduces considerably.


(B) Both A and R are true but R is NOT the correct explanation of

A



MCQ 53

Match List-I (Circuit name) with List-II (Circuit diagram) and select

the correct answer using the codes given below the lists:


www.gatehelp.com

Codes:

a b c d

(A) 1 2 3 4

(B) 2 1 3 4

(C) 1 2 4 3

(D) 2 1 4 3

MCQ 54

Thermal runaway is not possible in FET because as the temperature

of FET increase

(A) the mobility decrease

(B) the transonductance increase

(C) the drain current increase

(D) the mobility increases

MCQ 55

In a 741 op-amp, there is 20 dB/decade fall-off starting at a relatively

low frequency. This is due to the

(A) applied load (B) internal compensation

(C) impedance of the source (D) power dissipation in the chip


www.gatehelp.com

MCQ 56

The input differential stage of op-amp 741 is biased at about 10 Aμ current. Such a low current of the input stage gives

(A) high CMRR (B) high differential gain

(C) low differential gain (D) high input impedance

Which of these are corrent?(A) 1 and 2 (B) 1, 2 and 4

(C) 3 and 4 (D) 1, 2, 3 and 4

MCQ 57

The condition to be satisfied to prevent thermal runaway in a transistor amplifier where (PC = Power dissipated at Collector,

Junction temperatureTj = , Ambient temperatureTA = ,

tanThermal resis ceQ = ) is

(A) TP

Q1>

j

c

δδ (B) T

PQ1<

A

c

δδ

(C) TP

Q1<

j

c

δδ (D) T

PQ1>

A

c

δδ

MCQ 58


The function of bleeder resistance in filter circuit is to

1. maintain minimum current necessary for optimum inductor filter operation.

2. work as voltage divided in order to provide variable output from the supply.

3. provide discharge to capacitors so that output becomes zero when the circuit has been de-energised.

Which of these statements are correct?

(A) 1 and 2 (B) 2 and 3

(C) 1 and 3 (D) 1, 2 and 3

MCQ 59

Consider the following rectifier circuits:

1. Half-wave rectifier without filter.

2. Full-wave rectifier without filter.


www.gatehelp.com

3. Full-wave rectifier with series inductance filter.

4. Full-wave rectifier with capacitance filter

The sequence of these rectifier circuits in decreasing order of their ripple factor is(A) 1, 2, 3, 4 (B) 3, 4, 1, 2

(C) 1, 4, 3, 2 (D) 3, 2, 1, 4

MCQ 60

The use of a rectifier filter in a capacitor circuit gives satisfactory performance only when the load

(A) current is high (B) current is low

(C) voltage is high (D) voltage is low

MCQ 61

In a single-stage RC coupled common emitter amplifier, the phase shift at the lower 3 dB frequency is

(A) zero (B) 135c

(C) 180c (D) 225c

MCQ 62

The main drawback in the performance of shunt peaked wide band amplifier is

(A) too low gain at low frequency

(B) reduced gain at middle frequency

(C) poor phase response

(D) that the maximum gain of the stage is small

MCQ 63

A relaxation oscillator is one which

(A) has two stable states

(B) oscillates continuously

(C) relaxes indefinitely

(D) produces non-sinusoidal output


www.gatehelp.com

YEAR 2002

MCQ 64

Assertion (A): Operational amplifiers should have a high slew rate for good transient response.

Reason (R): Slew rate is the maximum rate of change of the output voltage of the operational amplifier when a large amplitude step is applied to its input.





MCQ 65

Assertion (A): An operational amplifier should have a low input offset current.

Reason (R): Input impedance of op-amp should be very high.





MCQ 66

Assertion (A): An operational amplifier can amplify very low frequency including d.c. signals.

Reason (R): op-amp uses very large coupling capacitor for cascading the various stages.






www.gatehelp.com

MCQ 67

Assertion (A): To obtain high switching speed in BJT based logic circuits, transistors are operated in active region.

Reason (R): In active region transistor works as a linear element.





MCQ 68

In a circuit, if the open loop gain is 106 and output voltage is 10 volt, the differential voltage should be

(A) 10 Vμ (B) 0.1 V

(C) 100 Vμ (D) 1 Vμ

MCQ 69

An operational amplifier possesses

(A) very large input resistance and very large output resistance

(B) very small input resistance and very small output resistance

(C) very large input resistance and very small output resistance

(D) very small input resistance and very large output

MCQ 70

A BJT is to be used in a high frequency circuit in common emitter amplifier. For a higher upper cur-off frequency ( ,C Cμ π and r0 have their usual meanings)

(A) Cμ should be as small as possible

(B) r0 and Cμ should be as large as possible

(C) Cπ and Cμ should be as large as possible

(D) r0, Cπ and Cμ should be as large as possible

MCQ 71

Consider the following statements regarding a common emitter amplifier. It can be converted into an oscillator by:


www.gatehelp.com

1. providing adequate positive feedback

2. phase shifting the output by 180c and feeding this phase-shifted

output to the input

3. using only a series tuned circuit as a load on the amplifier

4. using a negative resistance device as a load on the amplifier

Which of the above statements are correct?

(A) 1, 2, 3 and 4 (B) 1 and 2

(C) 1, 3 and 4 (D) 3 and 4

MCQ 72


In order to generate square wave from a sinusoidal input signal one

can use

1. Schmitt trigger circuit.

2. Clippers and amplifier.

3. Monostable multivibrators.

Which of the above statements/is are correct?

(A) 1 alone (B) 1 and 2

(C) 2 and 3 (D) 1, 2 and 3

MCQ 73

An op-amp circuit is shown in the figure given below. Different inputs

and output are given under List-I and List-II. Match List-I (Inputs)

with List-II (Outputs) and select the correct answer using the codes

given below the lists:


www.gatehelp.com

Codes:

a b c d

(A) 2 4 1 3

(B) 1 3 2 4

(C) 2 3 1 4

(D) 1 4 2 3


www.gatehelp.com

MCQ 74

The PIV rating of the diodes used in power supply circuits are chosen

by which one of the following criteria? (Vm is the peak input supply

voltage to the rectifier circuit used in the power supply)

(A) The diodes that are to be used in a full wave rectifier should be

rated V2 m and in bridge rectifier equal to Vm

(B) The diodes that are to be used in a full wave rectifier should

rectifier equal to V2 m

(C) All diodes should be rated for Vm only

(D) All diodes should be rated for V2 m

MCQ 75

An RC amplifier stage has a bandwidth of 500 kHz. What will be the

rise time of this amplifier stage?

(A) 0.35 sμ (B) 0.7 sμ

(C) 1.0 sμ (D) 2.0 sμ

MCQ 76

In the circuit shown above, If R R>> p1 and the impulses can

completely saturated transistor Q1, then the output voltage V0 will be


www.gatehelp.com

MCQ 77

The power input to an amplifier is 2 Wμ . The power gain of the amplifier is 40 dB. The output power of the amplifier is

(A) 80 Wμ (B) 200 Wμ

(C) 20 mW (D) 80 mW

MCQ 78

Given below are 2 sets of diagram one set shows 4 circuits with inputs; the order shows the output ( )V0 . Match List-I (inputs) with List-II (Outputs) and select the correct answer using the codes given below the lists:


www.gatehelp.com

Codes: a b c d(A) 1 3 2 4(B) 2 3 1 4(C) 1 4 2 3


www.gatehelp.com

(D) 2 4 1 3

MCQ 79

A class B push pull type amplifier with transformer coupled load uses two transistors rated 10 W each. What is the maximum power output one can obtain at the load from this circuit?

(A) 40 W (B) 50 W

(C) 60 W (D) 70 W

MCQ 80

In the circuit shown,

the transistor is biased at

(A) 0 mA (B) 5 mA

(C) 3.9 mA (D) 3

MCQ 81

An op-amp circuit is shown in the figure.


www.gatehelp.com

The output V0 will be (assume ideal op-amp)(A) equal to zero because the input is zero

(B) dependent on element values hence nothing can be predicted without a knowledge of element values

(C) a square wave varying between VCC+ and VCC−

(D) a sinusoidal wave of amplifier VCC

MCQ 82

An amplifier will generate stable sinusoidal oscillations if we provide feedback such that

(A) its pole lie close to jω-axis in the right half of s-plane

(B) its poles lie close to jω-axis in the left half of s-plane

(C) its poles lie on the ve+ real axis in s-plane

(D) its poles lie anywhere in s-plane

MCQ 83

A non-inverting op-amp is shown below (assume ideal o-amp)

The output voltage V0 for an input [2 (100 )]sin VV ti = +(A) / ( )sin t3 2 100 (B) ( )sin t3 100

(C) ( )sin t2 100 (D) ( ) /sin t3 100 1 2+

YEAR 2003

MCQ 84

Match List-I (Circuit) with List-II (Property) and select the correct answer using the codes given below the lists:

List-I


www.gatehelp.com

a. R-C coupled single-stage amplifier

b. Emitter follower

c. Common base amplifier

d. Darlington amplifier

List-II

1. Beta multiplier

2. Constant current source

3. Very high input impedance

4. Phase inverter with voltage gain

Codes: a b c d(A) 3 4 1 2(B) 4 3 1 2(C) 3 4 2 1(D) 4 3 2 1

MCQ 85

Consider the following statements in respect of a transistor R-C coupled amplifier:

1. The low frequency response is determined by the transistor junction capacitors.

2. The high frequency response is limited by coupling capacitors.

3. The Miller capacitance reduces the gain at high frequencies.

4. As the gain is increases the bandwidth gets reduced.

Which of these statements are correct?(A) 1 and 2 (B) 2 and 3

(C) 3 and 4 (D) 1 and 4

MCQ 86

Match List-I (Circuit Name) with List-II (Characteristics) and select the correct answer using the codes given below the lists:

List-I

a. Schmitt trigger

b. Monostable multivibrator

c. Astable multivibrator


www.gatehelp.com

d. Blocking oscillator

List-II

1. It needs a pulse transformer

2. It is used to generator gating pulse whose width can be controlled

3. It is a bistable circuit

4. It has no stable state

Codes: a b c d(A) 3 2 4 1(B) 2 3 1 4(C) 3 2 1 4(D) 2 3 4 1

MCQ 87

The biasing shown in the below circuit is

(A) Emitter bias (B) Self bias

(C) Potential divider bias (D) Bootstrap bias

MCQ 88

Which of the following main properties of a bipolar junction transistor make it necessary for the transistor to have bias stabilization?

1. Variation of VBE with temperature

2. Variation of hFE with temperature

3. Variation of ICO with temperature

4. Variation of hFE with transistor replacement


www.gatehelp.com

5. Variation of VBE with transistors replacement

6. Variation of ICO with transistor replacement

Select the correct answer using the codes given below;(A) 1, 2 and 6 (B) 1, 3 and 4

(C) 2, 3 and 5 (D) 3, 4, 5 and 6

MCQ 89

A triangular square wave generator uses

(A) A sine wave oscillation and a comparator

(B) An integrator and a comparator

(C) A differentiator and a comparator

(D) A sine wave oscillator and a clipper

MCQ 90

An amplifier has two identical cascaded stages. Each stage has a bandwidth of 20 kHz. The overall bandwidth shall approximately be equal to

(A) 10 kHz (B) 12.9 kHz

(C) 20 kHz (D) 28.3 kHz

MCQ 91

The common emitter current gain-bandwidth product of a transistor ( )fT is defined as the frequency at which

(A) Alpha of the transistor falls by 3 dB

(B) Beta of the transistor falls by 3 dB

(C) Beta of the transistor falls to unity

(D) Power gain of the transistor falls to unity

MCQ 92

Which of the following components control the low frequency of the R-C coupled amplifier?

1. Wiring capacitance

2. Parasitic capacitances of transistor

3. Coupling capacitances

4. Emitter bypass capacitance


www.gatehelp.com

Select the correct answer using the codes given below:

(A) 1 and 2 (B) 2 and 3

(C) 3 and 4 (D) 1, 2 and 4

MCQ 93

For a full-wave rectifier with shunt capacitor filter, the peak to peak

ripple voltage is

(A) /I f2 DC C (B) /I fDC C

(C) /I f2DC C (D) /I f4DC C

(where f = fundamental power line frequency, currentI DCDC = )

MCQ 94

In a BJT amplifier with the introduction of feedback, the input

impedance is reduced, output impedance is increased, bandwidth is

increased and distortion is reduced. The feedback is

(A) Voltage series (B) Current series

(C) Voltage shunt (D) Current shunt

MCQ 95

The stage marked X in the shown below architecture of a two-stage

op-amp is

(A) Direct coupled amplifier (B) Buffer amplifier

(C) Level shifter (D) Blocking oscillator

MCQ 96

The current through the resistor R in the below circuit is


www.gatehelp.com

(A) 1 mA (B) 4 mA

(C) 8 mA (D) 10 mA

MCQ 97

In the op-amp circuit shown above (assuming ideal op-amp)

(A) 5 VV0 =− (B) 5 VV0 =+

(C) V 00 = (D) 2 VV0 =−

MCQ 98

The function of the diode D in the timer circuit shown above is to


www.gatehelp.com

(A) Increase the charging time of C

(B) Decreases the charging time of C

(C) Increase the discharging time of C

(D) Decrease the discharging time of C

MCQ 99

Assertion (A): If the emitter bypass capacitor of an R-C coupled, CE amplifier gets disconnected, its voltage gain increases.

Reason (R): The unbypassed emitter resistor gives negative feedback.





MCQ 100

Assertion (A): A self-biased BJT circuit is more stable as compared to a fixed biased one.

Reason (R): A self-biased BJT circuit uses more components as compared to a fixed biased one.






www.gatehelp.com

MCQ 101

Assertion (A): Wien bridge oscillator is generally used as a variable audio frequency oscillator

Reason (R): By varying either the capacitor or resistor value in one of the arms of the bridge, the frequency of the Wien bridge oscillator can be varied.





YEAR 2004

MCQ 102

Consider the following circuits:

Which one of the following statements is correct?

(A) Circuit 1 is parallel connection and Circuit 2 is Darlington connection

(B) Circuit 1 is cascode connection and Circuit 2 is Darlington connection

(C) Circuit 1 is Darlington connection and Circuit 2 is cascode connection

(D) Circuit 1 is cascode connection and Circuit 2 is parallel connection

MCQ 103

An amplifier has a d.c. power supply of 15 V and draws a current of 10 mA. It produces an output of 5 V peak across a load resistance


www.gatehelp.com

of 600 Ω for a single frequency of 1 kHz. What will be its a.c. power output?

(A) 260 mW (B) 20.8 mW

(C) 520 mW (D) 40.6 mW

MCQ 104

The transfer function of a transistor amplifier is given by

A VV

j f j f14 10

14 10

4240v

s

0

5 6# #

= =+ +c cm m

Which one of the following gives the approximate upper 3 dB frequency f *

H . of the amplifier?(A) 4 10 Hz5

# (B) 2.2 10 Hz6#

(C) 4 10 Hz6# (D) 4.4 10 Hz6

#

MCQ 105

Which one of the following is a wide-band amplifier?

(A) RF amplifier (B) IF amplifier

(C) Video amplifier (D) AF amplifier

MCQ 106


In JFET amplifier, high frequency response can be improved by using peaking circuits containing inductors

1. in series with drain resistance RD

2. in series with the coupling capacitance

3. as a feedback element between drain and gate

Which of the statements given above are correct?(A) 1 and 2 (B) 2 and 3

(C) 1 and 3 (D) 1, 2 and 3

MCQ 107


If in a double tuned voltage amplifier, the mutually coupled secondary and primary are synchronously tuned with equal Q-values then for


www.gatehelp.com

the over-coupled case the maximum voltage amplification

(A) is greater than that for critical coupling and the amplifier characteristic is double peaked

(B) is less than that for critical coupling and the amplifier characteristics has a single peak

(C) is same as that for critical coupling and the amplifier characteristic is double peaked

(D) is less than that for critical coupling and the amplifier characteristic is doubled peaked

MCQ 108

A tuned amplifier has a voltage gain of 100 and a bandwidth of 10 kHz. It is required to increase the bandwidth of 20 kHz. This can be achieved by which one of the following ways?

(A) By doubling the gain

(B) By doubling the resonant frequency

(C) By halving the Q of the coil

(D) By halving the power supply voltage

MCQ 109

A d.c. to d.c. converter has an efficiency of 80% and is supplying a load of 24 W at 240 V. What is the current drawn from the battery if the converter is working from a batter of 12 V?

(A) 0.1 A (B) 2.0 A

(C) 2.5 A (D) 10 A

MCQ 110

Consider the following circuit:


www.gatehelp.com

What is the function of diode D2 in the above circuit?(A) To avoid saturation of the Op-Amp

(B) To provide negative feedback when the input is negative

(C) To reduce reverse breakdown voltage of D1

(D) As a buffer

MCQ 111


Which one of the following expressions for V0 is correct?

(A) V V R R RR R

z01 2

1 2= + ++

b l (B) V AVz0 =

(C) V AV RR1z0

2

1= +b l (D) V AV R R RR R

z01 2

1 2= + ++

b l

MCQ 112

Which one of the following statements is not correct in respect of a series transistor feedback voltage regulator?

(A) The regulation factor can be improved by increasing the hfe of the shunt transistor

(B) The regulation factor can be improved by increasing the resistance between the collector of the shunt transistor and the collector of the series transistor

(C) Output resistance can be reduced by using a Darlington pair in place of the series transistor

(D) Output resistance can be reduced by reducing the hfe of the shunt transistor


www.gatehelp.com

MCQ 113

Consider the following Op-Amp circuit:

What is the output voltage V0 in the above Op-Amp circuit?

(A) 10 V+ (B) 10 V−

(C) 11 V+ (D) 11 V−

MCQ 114


What is the value of R4 in the above circuit, if the voltage V− and V+

are to be amplified by the same amplification factor?

(A) 7 kΩ (B) 22 kΩ

(C) 33 kΩ (D) 35 kΩ

MCQ 115

What is the load current IL in the circuit below?


www.gatehelp.com

(A) 5 mA− (B) 10 mA−

(C) 25 mA+ (D) 50 mA+

MCQ 116

A 50 Hz symmetric square wave is applied to the RC circuit shown in

the diagram given below:

Which one the following is the correct shape of the output waveform?


www.gatehelp.com

MCQ 117


For the circuit shown above, which one of the following is a correct statement?

(A) D2 does not conduct for any value of Vi

(B) 10 Vv0 = for all values of 10 Vv >i

(C) 0 Vv0 = for all values of 0 Vv <i

(D) 10 Vv0 = for all values of 0 Vv >i

MCQ 118

Assertion (A): In a transistor switching circuit, it is desirable that the transistor should not be driven into hard saturation for fast switching applications.

Reason (R): When a transistor is under saturation on state, both its emitter-base and collector-base junctions remain under forward bias.






www.gatehelp.com

MCQ 119


What is the circuit shown above?

(A) Miller sweep (B) Bootstrap sweep

(C) Schmitt trigger (D) Triangular wave generator

MCQ 120

Match List-I (Application of the Circuit) with List-II (Circuit Name) and select the correct answer using the codes given below the lists:

List-I

a. Divider

b. Clips input voltage at two predetermined levels

c. Square wave generator

d. Narrow current pulse generator

List-II

1. Astable multivibrator

2. Schmitt trigger

3. Bistable multivibrator

4. Blocking oscillator

Codes:

a b c d

(A) 4 2 1 3

(B) 3 2 1 4

(C) 4 1 2 3

(D) 3 1 2 4


www.gatehelp.com

MCQ 121


How does the above circuit work

(A) As a logarithmic amplifier

(B) As a negative clipper

(C) As a positive clipper

(D) As a half-wave rectifier

MCQ 122


What is the type of circuit given above?

(A) Monostable (B) Ramp generator

(C) VCO (D) Bistable multivibrator

MCQ 123



www.gatehelp.com

What is voltage difference between collector and emitter ( )VCE in the above circuit?

(A) 10/3 V (B) 0 V

(C) 5 V (D) 3 V

MCQ 124

Consider the NPN transistor circuit shown below:

What if the output voltage V0 in the above circuit?

(A) 0 V (B) 12 V

(C) 9 V (D) 5 V

YEAR 2005

MCQ 125


A clamper circuit

1. adds or subtracts a dc voltage to or from a waveform.

2. does not change the shape of the waveform.


www.gatehelp.com

3. amplifies the waveform.

Which of the statements given above are correct?

(A) 1 and 2 (B) 2 and 3

(C) 1 and 3 (D) 1, 2 and 3

MCQ 126

The noise figure of a lossy network at room temperature equals the

(A) Gain of the network

(B) Attenuation factor of the network

(C) Equivalent noise temperature of the network

(D) Input noise power

MCQ 127

Assertion (A): In a Darlington connection, two transistors are connected in casecade in common emitter configuration.

Reason (R): The Darlington connection aims at making the current gain very high, almost equal to the product of beta of individual transistors.





MCQ 128

Assertion (A): It is possible to use the technique of additive amplification to get a wide band amplifier.

Reason (R): In additive amplifier, the overall gain of the amplifier is the sum of the gain of the individual amplifiers.






www.gatehelp.com

MCQ 129

Assertion (A): The self bias technique as used for a JFET cannot be used for establishing an operating point for the enhancement MOSFET.

Reason (R): The voltage drop across Rs is such that it reverse biased the gate


(B) Both A and R are true but R is NOT the correction explanation of A



MCQ 130

A transistor RC coupled amplifier is designed for a voltage and band gain of 20. But a measurement at a particular frequency shows the gain to be only 14. What is the likely phase shift at this frequency?

(A) 180c (B) 135c

(C) 90c (D) 45c

MCQ 131

What is the value of Rs required to self bias an N channel JFET with 10 VVp =− , 40 mAIDSS = and 5 VVGSQ =− ?

(A) 250 Ω (B) 500 Ω

(C) 750 Ω (D) 1500 Ω

MCQ 132

When a voltage divider biased amplifier has its Q-point near to the middle of the dc-load line, what is the maximum unclipped peak-to-peak output voltage?

(A) VCEQ (B) I rCQ L

(C) I r2 CQ L (D) V2 CEQ

MCQ 133

fT is the frequency at which the short circuit

(A) Common collector current gain has a magnitude of unity


www.gatehelp.com

(B) Common base current gain has a magnitude of unity

(C) Common emitter current gain has a magnitude of unity

(D) Common emitter current gain has a magnitude of /1 2

MCQ 134

Match List-I (Type of Amplifier) with List-II (Property) and select

the correct answer using the code given below the lists:

List-I

a. Single ended class A

b. Class AB push-pull

c. Class B push-pull

d. Class C

List-II

1. Medium efficiency with minimum distortion

2. High efficiency with crossover distortion

3. Harmonic generator with highest possible conversion efficiency

4. Poor conversion efficiency with minimum distortion

Codes:

a b c d

(A) 2 3 4 1

(B) 4 1 2 3

(C) 2 1 4 3

(D) 4 3 2 1

MCQ 135

A cascaded amplifier comprises N identical non-interacting stages,

each having a lower 3 dB frequency of fL . If f *L is the lower 3 dB

frequency of the cascaded amplifier, then which one of the following

is correct?

(A) f f*L L= (B) f f 2 1* /

L LN1= −

(C) /f f 2 1* /L L

N1= − (D) /f f N*L L=


www.gatehelp.com

MCQ 136


1. To achieve wide bandwidth, a transistor with a small C ,b c is chosen.

2. To achieve wide bandwidth, transistor with a small C ,b e is chosen.

3. To achieve wide bandwidth, transistor with a small base spreading resistance is chosen.


(A) 1 and 2 (B) 2 and 3

(C) 1 and 3 (D) 1, 2 and 3

MCQ 137

Three amplifiers each of gain ( / )A 20 and producing a phase of 60c are connected in tandem. The feedback loop is closed through a positive gain of 0.008. What should be the value of A0 for the system to be oscillatory?

(A) 10+ (B) 10−

(C) 250+ (D) .83 3+

MCQ 138

Match List-I (Name of the Oscillator) with List-II (Characteristics) and select the correct answer using the code given below the lists:

List-I

a. Colpitts Oscillator

b. Phase Shift Oscillator

c. Tunnel diode Oscillator

d. Relaxation Oscillator

List-II

1. RC Oscillator

2. LC Oscillator

3. Negative resistance Oscillator

4. Sweep circuits

Codes:

a b c d


www.gatehelp.com

(A) 1 2 3 4

(B) 2 1 3 4

(C) 1 2 4 3

(D) 2 1 4 3

MCQ 139

In a half-wave rectifier, if an a.c. supply is 60 Hz, then what is the a.c. ripple at output?

(A) 30 Hz (B) 60 Hz

(C) 120 Hz (D) 15 Hz

MCQ 140

Select the correct output ( )v0 wave-shape for a given input ( )v1 in the clamping network given below:


www.gatehelp.com

MCQ 141

Pulses of definite width can be obtained from irregular shaped pulses:

(A) When it is given as input to a monostable multivibrator

(B) When it is given as triggering signal to a bistable multivibrator

(C) When it is used as input to a Schmitt trigger

(D) When it is used as input to a pulse transformer

MCQ 142

For the circuit given below, what is IL equal to?

(A) /V RL (B) /V R

(C) R RV

L+ (D) R RV

2 L+

MCQ 143

For a given op-amp, CMRR 105= and differential gain 105= . What is the common mode gain of the op-amp?

(A) 1010 (B) 2 105#

(C) 105 (D) 1

MCQ 144

A half-wave rectifier having a resistance load of 1 kΩ rectifiers an a.c. voltage of 325 V peak value and the diode has a forward resistance of 100 Ω. What is the RMS value of the current?

(A) 295.4 mA (B) 94.0 mA

(C) 147.7 mA (D) 208.0 mA


www.gatehelp.com

MCQ 145

Silicon and Germanium are not suitable for fabrication of laser diode

because:

(A) Their absorption coefficients are very high

(B) Their emission coefficients are very low

(C) They have direct band gap

(D) They have indirect band gap

YEAR 2006

MCQ 146

In the circuit shown above, what is the value of transfer function

/I Ii0 ?

(A) ZZ

1

2− (B) ZZ

2

1−

(C) ZZ1

1

2+ b l (D) ZZ1

2

1+ b l

MCQ 147

Consider the following statements related to a shunt generator:

1. The full load voltage is lower than to load voltage.

2. The above lowering is partly due to voltage drop in armature

resistance.

3. The field current does not change with load and has no effect on

generated voltage.

Which of the statements give above are correct?

(A) 1, 2 and 3 (B) Only 1 and 2

(C) Only 2 and 3 (D) Only 1 and 3


www.gatehelp.com

MCQ 148

What is the phase shift between the input and output voltage in a common base small signal amplifier (assuming ideal coupling and bypass capacitors)?

(A) 180c (B) 180c−

(C) 0c (D) None of the above

MCQ 149

The transistor circuit shown in the figure given below is to function as an amplifier. If 3 mAICQ = , what is the value of VCC (approximate)?

(A) 15 V (B) 15 V−

(C) 10 V− (D) 13.5 V−

MCQ 150

(A) 3000 Ω (B) 1000/3 Ω

(C) 300 Ω (D) 100 Ω

MCQ 151

Consider the following parameters of a hybrid-π equivalent circuit of


www.gatehelp.com

BJT:

1. Transconductance ( )gm

2. hfe

3. hie

Which of the above parameters vary with temperature is similar manner (all of them decrease or all of them increase)? Select the correct answer using the code given below:

(A) only 1 and 2 (B) only 2 and 3

(C) only 1 and 3 (D) 1, 2 and 3

MCQ 152

What is the main advantage of a JFET-cascade amplifier?

(A) High voltage gain (B) Low output impedance

(C) Very low input capacitance (D) High input impedance

MCQ 153

When used for amplification, the output port side of BJT behaves as controlled current source. According to the above, the variation of which one of the following does not change the output current of an ideal BJT? (The BJT is being used in a common emitter amplifier circuit)

(A) Load resistance

(B) Collector to base bias voltage

(C) Both load resistance and collector to base bias voltage

(D) Base-emitter bias voltage

MCQ 154

Where does the operating point of a class B power amplifier lie?

(A) At the middle of a.c. a load line

(B) Approximately at collector cut-off on both the d.c. and a.c. load lines

(C) Inside the collector cut-off region on a.c. load line

(D) At the middle point of d.c. load line


www.gatehelp.com

MCQ 155

Consider the following statements in respect of a CC amplifier:

1. It performs a resistance transformation from low to high resistance.

2. Its current gain is close to unity.

3. Its voltage gain is close to unity.

4. Its frequency range is higher than that of a CE-stage.


(A) 1, 2 and 4 (B) 1 and 3

(C) Only 2 and 4 (D) 3 and 4

MCQ 156

A CE amplifier has 10 kRL Ω= . Given 1 khie Ω= , h 50fe = , h 0re = and 1/ 40 khce Ω= . What is the voltage gain?

(A) 500− (B) 400−

(C) 50− (D) 40−

MCQ 157

In an FET common source high frequency amplifier, which one of the following is the correct expression of input capacitance Ci?

(A) ( )C C A C1i gs v gd= + − (B) ( / )C C A C1 1i gs v gd= + −

(C) ( )C C A C1i gd v gs= + − (D) ( / )C C A C1 1i gd v gs= + −

MCQ 158

The drain gate capacitance of a junction FET is 2 pF. Assuming a common source voltage gain of 20, what is the input capacitance due to Miller effect?

(A) 21 pF (B) 40 pF

(C) 42 pF (D) 10 pF

MCQ 159

Assertion (A): All practical R-C phase shift oscillators generate sinusoidal oscillation with some amount of amplitude distortion, which cannot be avoided.

Reason (R): The amplitude distortion of a sinusoidal oscillator is


www.gatehelp.com

controlled by the onset of non-linearity of the amplifying device.





MCQ 160

Narrow pulses with adjustable mark to space ratio can be obtained from square wave input signal by using which of the following?

1. Schmitt trigger

2. Monostable multivibrator

3. Clippers

Select the correct answer using the code given below:(A) Only 1 (B) Only 2

(C) 1 and 2 (D) 2 and 3

MCQ 161

A differential amplifier has inputs, 1050 VV1 μ= and 950 VV2 μ= with CMRR = 1000. What is the error in the differential output?

(A) 10% (B) 1%

(C) 0.1% (D) 0.01%

MCQ 162


1. Stray capacitance at the input terminal of an op-amp effective introduces an additional phase lag network in feedback loop.

2. Stray capacitance depends upon the value of resistor used in feedback.

3. Low value of resistance has higher effects on stray capacitance


(A) 1, 2 and 3 (B) 2, 3 and 4

(C) 1, 3 and 4 (D) 1, 2 and 4


www.gatehelp.com

MCQ 163

In the given circuit, D1 is an ideal germanium diode and D2 is a silicon diode having its cut-in voltage as 0.7 V, forward resistance as 20 Ω and reverse saturation current ( )Is as 10 nA. What are the values of I and V for this circuit, respectively?

(A) 60 mA and 0 V (B) 50 mA and 0 V

(C) 53 mA and 0.7 V (D) 44 mA and 1.58 V

MCQ 164

The two stages of a cascade amplifier have individual upper cut-off frequencies 5 MHzf1 = and 3.33 MHzf2 = . What is the best approximation for the upper cut-off frequency of the cascade combination?

(A) 4.16 MHz (B) 3.33 MHz

(C) 2.5 MHz (D) 5.00 MHz

MCQ 165

An amplifier has an open loop gain of 1000 10! . Negative feedback is provided such that the gain variation remains within 0.1% What is the amount of feedback Fβ ?

(A) 1/10 (B) 1/9

(C) 9/100 (D) 9/1000

MCQ 166


We would be able to achieve broad banding in a common source FET amplifier, by

1. resonance between the shunt capacitance and a compensating inductance.


www.gatehelp.com

2. RC compensating network between source and drain.

3. connecting compensating network in series with the coupling capacitors.

Which of the statements given above is/are correct?

(A) Only 1 (B) 1 and 2

(C) 1 and 3 (D) 2 and 3

YEAR 2007

MCQ 167

Which one of the following gain equations is correct for a MOSFET common source amplifier? (gm is mutual conductance, and RD is load resistance at the drain)

(A) /A g RV m D= (B) A g RV m D=

(C) /( )A g R1V m D= + (D) /A R gV D m=

MCQ 168


The rise time of an amplifier is

(A) directly proportional to the upper 3 dB frequency

(B) inversely proportional to the upper 3 dB frequency

(C) directly proportional to the lower 3 dB frequency

(D) inversely proportional to the lower 3 dB frequency

MCQ 169

The 3 dB cut off frequency of a d.c. amplifier is 5 MHz. What is its rise time?

(A) 350 ns (B) 200 ns

(C) 70 ns (D) 35 ns

MCQ 170

For the amplifier shown in the figure given below, the lower cut-off frequency depends on which of the following?


www.gatehelp.com

(A) ,C CS E , internal junction capacitances of transistor

(B) Strong wiring capacitance ( ),C CW C

(C) , ,C C CS E C

(D) ,C CS E only

MCQ 171

In a class-B push-pull operation, the d.c. power drawn in 28 W. What is the power delivered by the amplifier at the ideal maximum efficiency of power conversion?

(A) 28 W (B) 14 W

(C) 22 W (D) 7 W

MCQ 172

Cascode amplifier when compared with a simple common-emitter amplifier provide which of the following?

(A) Higher voltage gain and same bandwidth

(B) Same voltage gain but higher bandwidth

(C) No change in either voltage gain or bandwidth

(D) Voltage gain less than one but bandwidth equal to fT

MCQ 173

Which of the following features are offered by a bipolar junction transistor amplifier in Darlington connection?

1. High voltage gain

2. High input impedance


www.gatehelp.com

3. High current gain

Select the correct answer using the code given below:

Codes:

(A) 1 and 2 only (B) 2 and 3 only

(C) 1 and 3 only (D) 1, 2 and 3

MCQ 174

Operating point shift can occur in an amplifier due to which one of the following?

(A) Input frequency variation

(B) Noise at the input

(C) Parasitic capacitances

(D) Power supply fluctuation

MCQ 175

For a CE amplifier, d.c. load line is which one of the following plots?

(A) IC versus VCE for a given value of ( )R RC E+ and VCC

(B) IB versus VEE for a given value of ( )R RC E+ and VCC

(C) IB versus VCE for a given value of IB

(D) IC versus VCB for a given value of IE

MCQ 176


The basic purpose of bias stabilization in a transistor circuit is to

1. increase the voltage and current gain of the ampilifier.

2. make the operating point of the transistor independent of temperature variation of the transistor.

3. make the operating point independent of the replacement of the same type, Ge or Si.



(C) 1 and 3 only (D) 1, 2 and 3


www.gatehelp.com

MCQ 177

Match List-I (Electronic Circuit) with List-II (Characteristic) and select the correct answer using the code given below the lists:

List-I

a. CE

b. CB

c. CC

d. Darlington Pair

List-II

1. The circuit introduces a phase inversion of 180c

2. The circuit is rarely used

3. The name, emitter follower is also used for the circuit

4. The circuit consists of two circuits connected in cascade

Codes:

a b c d

(A) 1 2 3 4

(B) 2 1 3 4

(C) 2 1 4 3

(D) 1 2 4 3

MCQ 178

In an amplifier, the power output is 2 W at 5 kHz, and 0.5 W at 50 Hz. If the input power is constant at 10 mW, what is the variation (approximate) of power gain in dB at two frequencies? ( . )log 2 0 3010 .

(A) 6 dB (B) 8 dB

(C) 3 dB (D) 16 dB

MCQ 179

A power supply has a full-load voltage of 24 V. What is its no-load voltage for %5 regulation (rounded to the nearest integer)?

(A) 12 V (B) 23 V

(C) 25 V (D) 6 V


www.gatehelp.com

MCQ 180

In a negative feedback amplifier, when is the input impedance

increased?

(A) If the signal sampled is a voltage

(B) If the signal sampled is a current

(C) If the feedback signal is a voltage

(D) if the feedback signal is a current

MCQ 181

A tuned amplifier has peak output at 2 MHz and quality factor

50. The bandwidth and 3 dB frequencies shall be at what values

respectively?

(A) 40 kHz, 2.02 MHz, 1.98 MHz

(B) 40 kHz, 2.04 MHz, 1.96 MHz

(C) 80 kHz, 2.04 MHz, 1.96 MHz

(D) 80 kHz, 2.08 MHz, 1.92 MHz

MCQ 182

The pinch-off voltage 6 VVp =+ for a P-channel JFET. If 2 VVGS =+

,what is the value of VDS at which it will enter into saturation region?

(A) 6 V− (B) 4 V−

(C) 8 V+ (D) 4 V+

MCQ 183

What is the output voltage V0 of the below circuit?


www.gatehelp.com

(A) 11 V− (B) 6 V

(C) 11 V (D) 6 V−

MCQ 184

What is the output voltage V0 of the below circuit?

(A) 1.1 V− (B) 1.1 V+

(C) 1.0 V (D) 10 V

MCQ 185

Assertion (A): Many power devices utilize the case itself as one of the principal current carrying terminals.

Reason (R): Such a connection maximizes the thermal resistance between the working semiconductors and the transistor case.




www.gatehelp.com



MCQ 186

Assertion (A): The three electrodes, Source, Drain and Gate of a FET correspond to Emitter, Base and Collector of a junction transistor respectively. Input signal is generally applied to the gate and gate voltage VG controls the electric field in the channel.

Reason (R): In the input circuit, the gate and the channel act like two plates of a capacitor. A charge of one polarity on the gate induces and equal and opposite charge in the channel. As a result the conductivity of the channel can be increased or decreased by VG .





YEAR 2008

MCQ 187


Bias stabilization in a BJT circuit is very important, because it

1. provides high voltage and current gain.

2. ensures large bandwidth of the amplifier.

3. keeps the operating point unchanged with change of temperature.

Which of the above statement(s) is/are correct?

(A) 1 and 2 (B) 2 and 3

(C) 3 only (D) 1 and 3

MCQ 188


Dominant-pole frequency compensation in an OP-AMP

1. increases the slow-rate of the OP-AMP


www.gatehelp.com

2. increases the stability of the OP-AMP

3. reduces the bandwidth of the OP-AMP

4. reduces the CMRR of the OP-AMP


(A) 1 and 3 only (B) 1, 2 and 4

(C) 1 and 2 only (D) 2 and 3 only

MCQ 189

In a practical oscillator circuit, which one of the following limits the amplitude of the oscillations?

(A) Onset of non-linearity

(B) Power supply voltage

(C) Oscillation frequencies

(D) Temperature of the active device

MCQ 190


Tuned amplifier

1. are wide band amplifiers

2. are used in radio transmitters and receivers

3. performance is determined by Q of the circuit



(C) 1 and 3 only (D) 1, 2 and 3

MCQ 191

A feed back amplifier has an open loop gain of 100− . If 4% of the output is fed back in a degenerative loop, what is the closed loop gain of the amplifier?

(A) .33 3− (B) 25−

(C) 20− (D) 25+

MCQ 192

Match List-I (Type of Feedback) with List-II (Effect on Rin and Rout


www.gatehelp.com

) and select the correct answer using the code given below the lists

List-I

a Voltage series

b. Voltage Shunt

c. Current Series

d. Current shunt

List-II

1. Rin increases and Rout decreases

2. Rin and Rout decrease

3. Rin and Rout increase

4. Rin decreases and Rout increases

Codes:

a b c d

(A) 1 4 3 2

(B) 3 2 1 4

(C) 3 4 1 2

(D) 1 2 3 4

MCQ 193

An amplifier has gain A 100 180c= , upper cut off frequency of 100 kHz and lower cut off frequency of 1 kHz. A negative feedback of

.0 1β = is added. Which one of the following is not correct?

(A) Gain becomes 100/11

(B) Lower cut off frequency becomes (100/11) Hz

(C) Upper cut off frequency becomes 1.1 MHz

(D) dB of feedback is log20 1110

MCQ 194

What is the collector circuit efficiency of a class B push-pull amplifier if

Vm = peak load voltage ,and

Vcc = collector supply voltage

(A) %VV

4 100cc

m#η π= (B) %V

V2 100

cc

m#η π=


www.gatehelp.com

(C) %VV

2 100m

cc#η π= (D) %V

V V4 100

m

cc m#η π= −

MCQ 195

Which of the following components are chosen to construct a d.c. power supply to supply 6 V d.c. voltage from 230 V a.c. to operate a tape recorder?

1. Step down transformer

2. Diodes

3. Resistors and capacitors

4. Three-pin voltage stabilizer


(A) 1, 2 and 3 only (B) 1 and 4 only

(C) 3 and 4 only (D) 1, 2, 3 and 4

MCQ 196

The figure shown is a circuit of which one of the following?

(A) Bridge rectifier (B) Voltage doubler

(C) Rectifier with filter (D) Comparator

MCQ 197

Which of the following components control the high frequency response of the R-C coupled amplifier?

1. Parasitic capacitances of the transistor

2. Coupling capacitance

3. Stray capacitance


www.gatehelp.com

4. Wiring capacitance



(C) 3 and 4 only (D) 1, 3 and 4

MCQ 198

The figure given below shows the circuit of which one of the following?

(A) Bi-stable multi-vibrator

(B) Schmitt trigger

(C) Monostable multi-vibrator

(D) Astable multi-vibrator

MCQ 199

The figure given above shows the transfer characteristics of which one

of the following

(A) Peak clipper (B) Bottom clipper

(C) Clamper (D) Two level clipper


www.gatehelp.com

MCQ 200

Match List-I (Name of the circuit) with List-II (Property of the circuit) and select the correct answer using the code given below the lists:

List-I

a. Pre-amplifier

b. Power amplifier

c. Rectifier circuit

d. Purely resistive circuit

List-II

1. Non-linear circuit

2. Lumped, linear, passive, bilaterial, finite circuit

3. Large signal amplifer

4. Small signal amplifier

Codes:

a b c d

(A) 4 2 1 3

(B) 1 3 4 2

(C) 4 3 1 2

(D) 1 2 4 3

MCQ 201

Assertion (A): A high value of resistor is connected across the diode in a clamper circuit for better performance.

Reason (R): If this resistor is not present, the circuit will respond to sudden decrease in the magnitude of the input pulse train, but the response to sudden increase in the amplitude will cause improper response.

(A) Both A and R are individually true and R is the correct explanation of A

(B) Both A and R are individually true but R is not the correct explanation of A




www.gatehelp.com

MCQ 202

Assertion (A): Complementary transistors are used for class B push-pull power amplifier.

Reason (R): We don’t need transformers if we use complementary transistors in class B push-pull power amplifiers.

(A) Both A and R are individually true and R is the correct explanation of A

(B) Both A and R are individually true but R is not the correct explanation of A



MCQ 203

In a class A amplifier, 15 VV ( )maxCE = and 1 VV ( )minCE = . The conversion efficiency for a series fed load will be equal to

(A) 25% (B) 23.33%

(C) 12.5% (D) 11.67%

MCQ 204

Neutralizing capacitors are normally used in

(A) Audio amplifier (B) Video amplofiers

(C) RF and IF amplifiers (D) Operational amplifiers

MCQ 205

Silicon diodes are less suited for low voltage rectifier operation because

(A) it cannot withstand high temperatures

(B) its reverse saturation current is low

(C) its cut-in voltage is high

(D) its breakdown voltage is high

MCQ 206

CE configuration is the most preferred transistor configuration when used as a switch because

(A) it requires only one power supply

(B) it requires low voltage or current for operating the switch


www.gatehelp.com

(C) it is easily understood by every one

(D) it has small ICEO

**********

ies - electronics engineering - analog electronic circuits

Documents

reason r

correct explanation

correct explanation

v ibe b

analog electronic circuitspage

thata v v21ce cc b v

feedback factor

trueies e t topic wise