Electronics and Communication Engineering

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Negative feedback is used in audio amplifiers to

Negative feedback is used in audio amplifiers to
  • A. operate class C
  • B. reduce distortion
  • C. increase distortion
  • D. increase gain
  • Correct Answer: Option B

For an amplifier, the coupling method which gives the highest gain in

For an amplifier, the coupling method which gives the highest gain in
  • A. impedance coupling
  • B. transformer coupling
  • C. capacitance coupling
  • D. resistance coupling
  • Correct Answer: Option B

High cut off frequency can be expected in case of

High cut off frequency can be expected in case of
  • A. common-base
  • B. common-emitter
  • C. common-collector
  • D. all of the above
  • Correct Answer: Option C

For high frequency response of a transistor amplifier, suitable model to use is

For high frequency response of a transistor amplifier, suitable model to use is
  • A. Kelvin network
  • B. Lattice network
  • C. Hybrid
  • D. T-network
  • Correct Answer: Option C

Transformer coupling in transistor amplifier circuits provides high efficiency, because

Transformer coupling in transistor amplifier circuits provides high efficiency, because
  • A. d.c. resistance is low
  • B. collector voltage is stepped up
  • C. flux linkages are incomplete
  • D. all of the above
  • Correct Answer: Option A

A delay equalizer is a

A delay equalizer is a
  • A. low pass filter
  • B. band pass filter
  • C. all pass filter
  • D. high pass filter
  • Correct Answer: Option B

A pulse transformer uses

A pulse transformer uses
  • A. ferrite core
  • B. air core
  • C. iron core
  • D. copper core
  • Correct Answer: Option A

A boot strap generally incorporates

A boot strap generally incorporates
  • A. CB configuration
  • B. CE configuration
  • C. emitter follower
  • D. none of the above
  • Correct Answer: Option A

Low frequency response of amplifier is mainly limited by

Low frequency response of amplifier is mainly limited by
  • A. input capacitor
  • B. bypass capacitor
  • C. output capacitor
  • D. biasing capacitor
  • Correct Answer: Option B

For an ideal noise free transistor amplifier the noise factor is

For an ideal noise free transistor amplifier the noise factor is
  • A. zero
  • B. zero dB
  • C. 1 dB
  • D. depends on other factors
  • Correct Answer: Option B

For a transistor to have-a larger β it must have and a

For a transistor to have-a larger β it must have and a
  • A. close to zero
  • B. close to 0.5
  • C. close to unity
  • D. nearly infinite
  • Correct Answer: Option C

In common base amplifier the current gain is less than one, but the voltage gain may be anywhere from

In common base amplifier the current gain is less than one, but the voltage gain may be anywhere from
  • A. 0.5 to 1
  • B. 1 to 5
  • C. 5 to 10
  • D. 50 to 2000
  • Correct Answer: Option D

The conversion or collector circuit efficiency is a measure

The conversion or collector circuit efficiency is a measure
  • A. how successfully the active device converts D.C. power to A.C. signal power
  • B. how much distortion in output is reduced with respect to input
  • C. how successfully the active device converts A.C. power to D.C. signal power
  • D. none of the above
  • Correct Answer: Option A

In a CB amplifier the maximum efficiency could be

In a CB amplifier the maximum efficiency could be
  • A. 99%
  • B. 85%
  • C. 50%
  • D. 25%
  • Correct Answer: Option D

In CB amplifier the distortion of the input voltage waveform may occur due to

In CB amplifier the distortion of the input voltage waveform may occur due to
  • A. very low input resistance of an amplifier
  • B. very high input resistance of the amplifier
  • C. improper biasing
  • D. ripples in power supply
  • Correct Answer: Option A

Harmonic distortion in CB amplifier may be least when the load resistance is

Harmonic distortion in CB amplifier may be least when the load resistance is
  • A. negligible
  • B. very low
  • C. very high
  • D. infinite
  • Correct Answer: Option C

In CE amplifier

In CE amplifier
  • A. input and output are in phase
  • B. phase difference between input and output is 30° to 90°
  • C. phase difference between input and output is 60° to 120°
  • D. output is inverted with respect to its input voltage
  • Correct Answer: Option D

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

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
  • Correct Answer: Option C

Linear transistor circuits always operate in

Linear transistor circuits always operate in
  • A. saturation region
  • B. cut off region
  • C. active region
  • D. passive region
  • Correct Answer: Option C

The voltage gain of which transistor configuration is less than unity?

The voltage gain of which transistor configuration is less than unity?
  • A. CB
  • B. CE
  • C. CC
  • D. None
  • Correct Answer: Option C