50 TOP OP-AMP Questions and Answers pdf | MCQs

OP AMP Questions and Answers pdf :-

1. A differential amplifier ……………..

  1. is a part of an Op-amp
  2. has one input and one output
  3. has two outputs
  4. answers (1) and (2)
    Ans : 4

2. When a differential amplifier is operated single-ended, …………

  1. the output is grounded
  2. one input is grounded and signal is applied to the other
  3. both inputs are connected together
  4. the output is not inverted

Ans : 2

3. In differential-mode, …………….

  1. opposite polarity signals are applied to the inputs
  2. the gain is one
  3. the outputs are of different amplitudes
  4. only one supply voltage is used

Ans : 1

OP AMP Questions and Answers pdf
OP AMP Questions and Answers pdf

4. In the common mode, ……………

both inputs are grounded
the outputs are connected together
an identical signal appears on both the inputs
the output signal are in-phase
Ans : 3

5. The common-mode gain is ………..

very high
very low
always unity
unpredictable
Ans : 2

6. The differential gain is ………

very high
very low
dependent on input voltage
about 100
Ans : 1

7. If ADM = 3500 and ACM = 0.35, the CMRR is ……….

1225
10,000
80 dB
answers (1) and (3)
Ans : 4

8. With zero volts on both inputs, an OP-amp ideally should have an output ………..

equal to the positive supply voltage
equal to the negative supply voltage
equal to zero
equal to CMRR
Ans : 3

9. Of the values listed, the most realistic value for open-loop voltage gain of an OP-amp is ……

1
2000
80 dB
100,000
Ans : 4

10. A certain OP-amp has bias currents of 50 µA. The input offset current is ……..

700 nA
99.3 µA
49.7 µA
none of these
Ans : 1

11. The output of a particular Op-amp increases 8V in 12µs. The slew rate is …….

90 V/µs
0.67 V/µs
1.5 V/µs
none of these
Ans : 2

12. For an Op-amp with negative feedback, the output is …….

equal to the input
increased
fed back to the inverting input
fed back to the noninverting input
Ans : 3

13. The use of negative feedback ………

reduces the voltage gain of an Op-amp
makes the Op-amp oscillate
makes linear operation possible
answers (1) and (2)
Ans : 4

14. Negative feedback ………..

increases the input and output impedances
increases the input impedance and bandwidth
decreases the output impedance and bandwidth
does not affect impedance or bandwidth
Ans : 2

15. A certain noninverting amplifier has Ri of 1 kO and Rf of 100 kO. The closed-loop voltage gain is ………

100,000
1000
101
100
Ans : 3

16. If the feedback resistor in Q15 (above question) is open, the voltage gain …….

increases
decreases
is not affected
depends on Ri
Ans : 1

17. A certain inverting amplifier has a closed-loop voltage gain of 25. The Op-amp has an open-loop voltage gain of 100,000. If an Op-amp with an open-loop voltage gain of 200,000 is substituted in the arrangement, the closed-loop gain ……..

doubles
drops to 12.5
remains at 25
increases slightly
Ans : 3

18. A voltage follower ……….

has a voltage gain of 1
is noninverting
has no feedback resistor
has all of these
Ans : 4

19. The Op-amp can amplify

a.c. signals only
d.c. signals only
both a.c. and d.c. signals
neither d.c. nor a.c. signals
Ans : 3

20. The input offset current equals the ……….

difference between two base currents
average of two base currents
collector current divided by current gain
none of these
Ans : 1

21. The tail current of a differential amplifier is …….

half of either collector current
equal to either collector current
two times either collector current
equal to the difference in base currents
Ans : 3

22. The node voltage at the top of the til resistor is closes to ……….

collector supply voltage
zero
emitter supply voltage
tail current times base resistance
Ans : 2

23. The tail current in a differential amplifier equals …….

difference between two emitter currents
sum of two emitter currents
collector current divided by current gain
collector voltage divided by collector resistance
Ans : 2

24. The differential voltage gain of a differential amplifier is equal to RC divided by …….

r’e
r’e/2
2r’e
RE
Ans : 3

25. The input impedance of a differential amplifier equals r’e times ……

ß
RE
RC

Ans : 4

26. A common-mode signal is applied to ……….

the noninverting input
the inverting input
both iputs
top of the tail resistor
Ans : 3

27. The common-mode voltage gain is ………

smaller than differentail voltage gain
equal to differential voltage gain
greater than differential voltage gain
none of the above
Ans : 1

28. The input stage of an Op-amp is usually a ……….

differential amplifier
class B push-pull amplifier
CE amplifier
swamped amplifier
Ans : 1

29. The common-mode voltage gain of a differential amplifier is equal to RC divided by ……..

r’e
2r’e
r’e/2
2RE
Ans : 4

30. Current cannot flow to ground through …….

a mechanical ground
an a.c. ground
a virtual ground
an ordinary ground
Ans : 3

operational amplifier objective type Questions and Answers pdf free download :-

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