1. In an ideal operational amplifier, the open-loop gain is:
A. Zero
B. 1
C. Infinite
D. 1000
Answer: C. Infinite
2. The input impedance of an ideal operational amplifier is:
A. Zero
B. Low
C. Infinite
D. Variable
Answer: C. Infinite
3. The output impedance of an ideal operational amplifier is:
A. Zero
B. Low
C. High
D. Variable
Answer: A. Zero
4. The ideal op-amp should have an infinite common-mode rejection ratio (CMRR). This means:
A. The op-amp can reject all signals
B. The op-amp will reject both input signals equally
C. The op-amp rejects common-mode signals completely
D. The op-amp will have high input impedance
Answer: C. The op-amp rejects common-mode signals completely
5. The typical input offset voltage of an operational amplifier is:
A. Zero
B. Very small (millivolt range)
C. 1V
D. Large (greater than 10V)
Answer: B. Very small (millivolt range)
6. In an ideal op-amp, the voltage difference between the inverting and non-inverting inputs is:
A. Infinite
B. Zero
C. Equal to the input voltage
D. Dependent on the supply voltage
Answer: B. Zero
7. The voltage gain of an operational amplifier in an open-loop configuration is:
A. Constant
B. Extremely high, but finite
C. High, but adjustable
D. Low
Answer: B. Extremely high, but finite
8. The gain of a non-inverting amplifier is given by the formula:
A. 1+RfR11 + \frac{R_f}{R_1}
B. RfR1\frac{R_f}{R_1}
C. 1−RfR11 – \frac{R_f}{R_1}
D. R1Rf\frac{R_1}{R_f}
Answer: A. 1+RfR11 + \frac{R_f}{R_1}
9. The primary function of an inverting amplifier is to:
A. Amplify the input signal without changing the phase
B. Amplify the input signal with a 180-degree phase shift
C. Provide voltage buffering
D. Integrate or differentiate the signal
Answer: B. Amplify the input signal with a 180-degree phase shift
10. A differential amplifier amplifies the difference between:
A. Two input signals
B. A signal and ground
C. A positive and negative input signal
D. The signal and the feedback
Answer: A. Two input signals
11. Which of the following is a common application of an op-amp in a voltage follower configuration?
A. Amplifying weak signals
B. Providing impedance matching
C. Signal mixing
D. Signal differentiation
Answer: B. Providing impedance matching
12. In an op-amp-based integrator, the output is the:
A. Sum of the input signal with respect to time
B. Derivative of the input signal
C. Integral of the input signal with respect to time
D. Input signal multiplied by a constant
Answer: C. Integral of the input signal with respect to time
13. A differentiator circuit using an op-amp produces an output that is:
A. Proportional to the input voltage
B. The integral of the input signal
C. The derivative of the input signal
D. Equal to the input signal
Answer: C. The derivative of the input signal
14. An op-amp-based Schmitt trigger is primarily used for:
A. Amplifying signals
B. Filtering noise and providing a clean output
C. Rectifying AC signals
D. Integrating signals
Answer: B. Filtering noise and providing a clean output
15. The ideal voltage gain of an operational amplifier in open-loop configuration is:
A. Zero
B. 1
C. Infinite
D. 10
Answer: C. Infinite
16. A negative feedback in an operational amplifier leads to:
A. A decrease in bandwidth
B. Increased output impedance
C. Reduced distortion and stabilization of gain
D. Increased power consumption
Answer: C. Reduced distortion and stabilization of gain
17. In an op-amp circuit, when the output voltage is negative and the input signal is positive, this is an example of:
A. Positive feedback
B. Negative feedback
C. Inverting configuration
D. Non-inverting configuration
Answer: C. Inverting configuration
18. A voltage comparator using an op-amp is used to:
A. Compare two input voltages and output a signal indicating the higher voltage
B. Provide an amplified output signal
C. Rectify the input AC voltage
D. Integrate or differentiate the input voltage
Answer: A. Compare two input voltages and output a signal indicating the higher voltage
19. An op-amp with a high gain is ideal for use in which of the following circuits?
A. Active filters
B. Oscillators
C. High-precision amplifiers
D. All of the above
Answer: D. All of the above
20. A practical application of an op-amp in a signal conditioning circuit is:
A. Voltage regulation
B. Voltage amplification and filtering
C. Voltage comparator
D. High-speed switching
Answer: B. Voltage amplification and filtering