50 Prime Amplifiers with Negative Feedback

50 Prime Amplifiers with Negative Feedback Questions and Answers pdf

1. When negative voltage feedback is applied to an amplifier, its voltage
gain ……………….
1. Is increased
2. Is reduced
3. Remains the same
4. None of the above
Ansr : 2
2. The value of negative feedback fraction is always …………….
1. Less than 1
2. More than 1
3. Equal to 1
4. None of the above
Ansr : 1
3. If the output of an amplifier is 10 V and 100 mV from the output is fed back to
the input, then feedback fraction is ………..
1. 10
2. 1
3. 01
4. 15
Ansr : 3
4. The gain of an amplifier without feedback is 100 db. If a negative feedback of 3
db is applied, the gain of the amplifier will become …………..
1. 5 db
2. 300 db
3. 103 db
4. 97 db
Ansr : 4
5. If the feedback fraction of an amplifier is 0.01, then voltage gain with negative

feedback is approximately………..
1. 500
2. 100
3. 1000
4. 5000
Ansr : 2
6. A feedback circuit usually employs ……………… network
Resistive
Capacitive
Inductive
None of the above
Ansr : 1
7. The gain of an amplifier with feedback is known as ………….. gain
Resonant
Open loop
Closed loop
None of the above
Ansr : 3
8. When voltage feedback (negative) is applied to an amplifier, its input
impedance ………….
Is decreased
Is increased
Remains the same
None of the above
Ansr : 2
9. When current feedback (negative) is applied to an amplifier, its input
impedance …………..
Is decreased
Is increased
Remains the same
None of the above
Ansr : 1
10. Negative feedback is employed in ……………..
Oscillators
Rectifiers
Amplifiers
None of the above
Ansr : 3
11. Emitter follower is used for …………
Current gain
Impedance matching
Voltage gain
None of the above
Ansr : 2
12. The voltage gain of an emitter follower is ………..
Much less than 1
Approximately equal to 1
Greater than 1
None of the above
Ansr : 2
13. When current feedback (negative) is applied to an amplifier, its output
impedance ……..
Is increased
Is decreased
Remains the same
None of the above
Ansr : 1
14. Emitter follower is a ……………….. circuit
Voltage feedback
Current feedback
Both voltage and current feedback
None of the above
Ansr : 2
15. If voltage feedback (negative) is applied to an amplifier, its output
impedance …………..
Remains the same
Is increased
Is decreased
None of the above
Ansr : 3
16. When a negative voltage feedback is applied to an amplifier, its
bandwidth……….
Is increased
Is decreased
Remains the same
Insufficient data
Ansr : 1
17. An emitter follower has ………… input impedance
Zero

Low
High
None of the above
Ansr : 3
19. The output impedance of an emitter follower is ……….
High
Very high
Almost zero
Low
Ansr : 4