Analog Integrated Circuits (Operational Amplifiers) — MCQs – EE

1. An operational amplifier (Op-Amp) is a:
(A) Current amplifier
(B) Voltage amplifier
(C) Power amplifier
(D) Switching device

2. The ideal Op-Amp has an input impedance that is:
(A) Zero
(B) Very low
(C) Very high
(D) Infinite

3. The ideal Op-Amp has an output impedance that is:
(A) Infinite
(B) Very high
(C) Zero
(D) Moderate

4. The ideal voltage gain of an Op-Amp is:
(A) Zero
(B) Unity
(C) Very high
(D) Infinite

5. The two input terminals of an Op-Amp are:
(A) Base and Emitter
(B) Inverting and Non-inverting
(C) Source and Drain
(D) Positive and Negative

6. The output of an Op-Amp depends on:
(A) Difference between the two input voltages
(B) Sum of input voltages
(C) Product of input voltages
(D) Ratio of input voltages

7. The inverting input is denoted by:
(A) (+)
(B) (–)
(C) (×)
(D) (÷)

8. The non-inverting input is denoted by:
(A) (–)
(B) (+)
(C) (×)
(D) (=)

9. The common-mode rejection ratio (CMRR) of an ideal Op-Amp is:
(A) Zero
(B) One
(C) Infinite
(D) Very small

10. The slew rate of an Op-Amp refers to:
(A) The rate of change of input voltage
(B) The rate of change of output voltage
(C) The input offset current
(D) The bias current

11. The power supply pins of an Op-Amp are generally labeled as:
(A) +Vcc and –Vcc
(B) +Vin and –Vin
(C) +Vout and –Vout
(D) +Vs and –Vs

12. In an inverting amplifier, the input signal is applied to:
(A) Non-inverting terminal
(B) Inverting terminal
(C) Both terminals
(D) Ground

13. In an inverting amplifier, the output signal is:
(A) In phase with input
(B) Out of phase by 180°
(C) Amplified without inversion
(D) Zero phase shift

14. In a non-inverting amplifier, the output signal is:
(A) In phase with input
(B) Out of phase by 90°
(C) Out of phase by 180°
(D) Randomly phased

15. The voltage gain of a non-inverting amplifier is always:
(A) Less than 1
(B) Equal to 1
(C) Greater than or equal to 1
(D) Negative

16. The voltage gain of an inverting amplifier is:
(A) Positive
(B) Negative
(C) Zero
(D) Unity

17. The input offset voltage in an Op-Amp is:
(A) The input voltage required to make output zero
(B) The output voltage when input is zero
(C) The bias voltage at the non-inverting terminal
(D) None of the above

18. The virtual ground concept is applicable to:
(A) Non-inverting amplifier
(B) Inverting amplifier
(C) Differential amplifier
(D) Comparator

19. A summing amplifier is based on which configuration?
(A) Inverting amplifier
(B) Non-inverting amplifier
(C) Differential amplifier
(D) Integrator

20. An Op-Amp integrator produces output proportional to the:
(A) Input voltage
(B) Derivative of input
(C) Integral of input
(D) Inverse of input

21. An Op-Amp differentiator produces output proportional to the:
(A) Input voltage
(B) Derivative of input
(C) Integral of input
(D) Constant voltage

22. A voltage follower has a voltage gain of:
(A) 0
(B) 1
(C) Greater than 1
(D) Infinite

23. The main advantage of a voltage follower is:
(A) Voltage amplification
(B) Current amplification
(C) High input and low output impedance
(D) Phase inversion

24. An instrumentation amplifier is mainly used for:
(A) Power control
(B) High-gain differential signal amplification
(C) Voltage regulation
(D) Oscillation generation

25. A comparator is an Op-Amp circuit that:
(A) Compares two voltages and gives digital output
(B) Amplifies both inputs
(C) Works as a rectifier
(D) Integrates the signal

26. A Schmitt trigger is used to:
(A) Generate a sine wave
(B) Eliminate noise and create a clean digital signal
(C) Perform integration
(D) Produce DC voltage

27. The open-loop gain of an Op-Amp is:
(A) Very small
(B) Moderate
(C) Very high
(D) Constant

28. The bandwidth of an ideal Op-Amp is:
(A) Zero
(B) Limited
(C) Infinite
(D) Fixed

29. The 741 Op-Amp is a:
(A) FET-based amplifier
(B) General-purpose integrated Op-Amp
(C) Power amplifier
(D) Audio amplifier

30. Op-Amps are widely used in:
(A) Filters
(B) Oscillators
(C) Signal conditioning circuits
(D) All of the above