Electronics and Communication Engineering

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Self bias is an example of __________ feedback that tends to stabilize the drain current against changes in temperature and JFET replacement.

Self bias is an example of __________ feedback that tends to stabilize the drain current against changes in temperature and JFET replacement.
  • A. variable
  • B. low
  • C. negative
  • D. positive
  • Correct Answer: Option C

The common-drain amplifier, better known as the source follower, has a voltage gain __________ and the output signal is __________ with the input signal.

The common-drain amplifier, better known as the source follower, has a voltage gain __________ and the output signal is __________ with the input signal.
  • A. approaching unity, in phase
  • B. approaching unity, out of phase
  • C. is very high, in phase
  • D. is very high, in reverse phase
  • Correct Answer: Option A

One of the major applications of JFET is in

One of the major applications of JFET is in
  • A. switching
  • B. constant current-source
  • C. constant voltage-source
  • D. electron flow regulation
  • Correct Answer: Option A

When a JFET is cut off, it’s like an __________ switch and when it is saturated, it’s like a __________ switch.

When a JFET is cut off, it’s like an __________ switch and when it is saturated, it’s like a __________ switch.
  • A. closed, open
  • B. open, closed
  • C. open, open
  • D. closed, closed
  • Correct Answer: Option B

In a resistance loaded amplifier, the gain decreases at high frequencies because

In a resistance loaded amplifier, the gain decreases at high frequencies because
  • A. decreasing reactance of the stray CT
  • B. increasing reactance of the stray CT
  • C. increasing reactance of CT
  • D. decreasing reactance of CT
  • Correct Answer: Option A

Which of the following contributes to harmonics distortion in amplifiers?

Which of the following contributes to harmonics distortion in amplifiers?
  • A. Positive feedback
  • B. Presence of noise
  • C. Defective active device
  • D. Non-linearity in active device
  • Correct Answer: Option D

Logarithmic amplifiers are used in

Logarithmic amplifiers are used in
  • A. adders
  • B. dividers
  • C. multipliers
  • D. all of the above
  • Correct Answer: Option B

In high frequency region, an amplifier behaves like a

In high frequency region, an amplifier behaves like a
  • A. band pass filter
  • B. low pass filter
  • C. high pass filter
  • D. any of the above
  • Correct Answer: Option B

Which amplifier will be preferred for highest gain?

Which amplifier will be preferred for highest gain?
  • A. Darlington's pair
  • B. Single stage amplifier
  • C. Cascade amplifier
  • D. Depends on the circuitry
  • Correct Answer: Option C

A cascade amplifier will have higher cut off frequency

A cascade amplifier will have higher cut off frequency
  • A. equal to that of single stage amplifier
  • B. less than that of single stage amplifier
  • C. more than that of single stage amplifier
  • D. none of these
  • Correct Answer: Option B

Class-B amplifier has less efficiency compared to

Class-B amplifier has less efficiency compared to
  • A. class A
  • B. class B
  • C. class C
  • D. class A, AB and C
  • Correct Answer: Option A

Which of the following is not necessarily the advantages of a push pull amplifier?

Which of the following is not necessarily the advantages of a push pull amplifier?
  • A. It gives more output
  • B. It removes odd a well as even harmonics
  • C. There is no effect of ripple of the power supply
  • D. It consumes least power
  • Correct Answer: Option B

Which of the following statements is false?

Which of the following statements is false?
  • A. Push pull signals are equal and opposite in phase
  • B. Class AB operation cannot be used for a push pull audio power output phase
  • C. A push pull output transformer has a centre-tapped primary
  • D. All of the above
  • Correct Answer: Option B

A push pull amplifier balance out

A push pull amplifier balance out
  • A. odd harmonics
  • B. even harmonics
  • C. both odd as well as even harmonics
  • D. neither odd nor even harmonics
  • Correct Answer: Option A

In voltage amplifiers, the load resistance

In voltage amplifiers, the load resistance
  • A. should be a small as possible
  • B. should be as large as possible
  • C. must be equal to output impedance
  • D. must be half of output impedance
  • Correct Answer: Option B

Which distortion is least objectionable in case of audio amplifiers?

Which distortion is least objectionable in case of audio amplifiers?
  • A. Phase distortion
  • B. Frequency distortion
  • C. Harmonic distortion
  • D. Inter-modulation distortion
  • Correct Answer: Option A

Which of the following method cannot be used to increase the bandwidth for cascaded RF amplifier stages?

Which of the following method cannot be used to increase the bandwidth for cascaded RF amplifier stages?
  • A. Wave traps in each stage
  • B. Stagger tuning
  • C. A shunt damping resistor across each tuned circuit
  • D. Doubled tuned transformers with tighter coupling
  • Correct Answer: Option A

Which of the following circuit has the greatest bandwidth?

Which of the following circuit has the greatest bandwidth?
  • A. fr = 455 MHz; Q = 10
  • B. fr = 455 MHz; Q = 100
  • C. fr = 1 MHz; Q = 100
  • D. fr = 1 MHz; Q = 10
  • Correct Answer: Option D

In an amplifier if conductor during the cycle is from 0 to 90° and again from 180° to 270°, the amplifier will be termed as

In an amplifier if conductor during the cycle is from 0 to 90° and again from 180° to 270°, the amplifier will be termed as
  • A. class A
  • B. class B
  • C. class C
  • D. class AB
  • Correct Answer: Option B

A sine wave is passed through an amplifier which severely limits it symmetrically. If then passes to a second amplifier which is narrow band and tuned to the frequency of the original sine wave. What will be the output wave from this second amplifier?

A sine wave is passed through an amplifier which severely limits it symmetrically. If then passes to a second amplifier which is narrow band and tuned to the frequency of the original sine wave. What will be the output wave from this second amplifier?
  • A. A square wave of the same frequency as that of the original sine wave
  • B. A square wave of double the frequency of that of original sine wave
  • C. A sine wave of constant amplitude at the frequency of the original sine wave
  • D. A sine wave of constant amplitude at double frequency of the original sine wave
  • Correct Answer: Option C