BJT Amplifiers and Oscillators MCQs

Question 1

In the expression for voltage gain with negative voltage feedback, the term 1 + Am mv is known as

Accepted Answer

sacrifice factor (d) none of the above

Answer

gain factor

Answer

feedback factor

Question 2

Feedback circuit ____frequency.

Accepted Answer

is independent of

Answer

is strongly dependent on

Answer

is moderately dependent on

Answer

none of the above

Question 3

The basic purpose of applying negative voltage feedback is to

Accepted Answer

reduce distortion

Answer

increase voltage gain

Answer

keep the temperature within limits

Answer

none of the above

Question 4

If the voltage gain of an amplifier without feedback is 20 and with negative voltage feedback it is 12, then feedback fraction is

Accepted Answer

Answer

5/3

Answer

3/5

Answer

1/5(d) 0.033

Question 5

In an emitter follower, we employ negative current feedback

Accepted Answer

100%

Answer

50%

Answer

25%

Answer

75%

Question 6

An amplifier has an open loop voltage gain of 1,00,000. With negative voltage feedback, the voltage gain is reduced to 100. What is the scrifice factor?

Accepted Answer

1000

Answer

100

Answer

5000

Answer

none of the above

Question 7

In the above question, what will happen to circuit performance?

Accepted Answer

input impedance is increased 1000 times

Answer

distortion is increased 1000 times

Answer

output impedance is increased 1000 times

Answer

none of the above

Question 8

The output and input voltage of an emitter follower have a phase difference of

Accepted Answer

270?

Answer

180?

Answer

90?

Question 9

It is most necessary to control signal-to-noise ratio at

Accepted Answer

initial stage

Answer

driver stage

Answer

output stage

Answer

detector stage