Explore topic-wise MCQs in Electronics.

This section includes 194 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics knowledge and support exam preparation. Choose a topic below to get started.

1.

The ideal output impedance for an is 0 .

A. True
B. False
Answer» B. False
2.

The resistors and in an op-amp circuit control ______ .

A. positive feedback and current gain
B. negative feedback and power gain
C. negative feedback and voltage gain
D. open and closed loop gain
Answer» D. open and closed loop gain
3.

The magnitude of closed-loop voltage gain () of an inverting amplifier equals:

A. the ratio of the input resistance to the feedback resistance
B. the open-loop voltage gain
C. the feedback resistance divided by the input resistance
D. the input resistance
Answer» D. the input resistance
4.

The open-loop voltage gain () of an op-amp is the

A. external voltage gain the device is capable of
B. internal voltage gain the device is capable of
C. most controlled parameter
D. same as
Answer» C. most controlled parameter
5.

It takes 4 s for the output voltage of an op-amp to rise from –14 V to +14 V. The of this op-amp is 3.5 V/s.

A. True
B. False
Answer» C.
6.

If a noninverting amplifier has an R of 1000 ohms and an R of 2.5 kilohms, what is the R voltage when 1.42 mV is applied to the correct input?

A. 3.5 mV
B. ground
C. 1.42 mV
D. 0.56 mV
Answer» D. 0.56 mV
7.

Input impedance [(I)] of an inverting amplifier is approximately equal to:

A. +
B.
Answer» B. –
8.

Current actually flows into or out of a .

A. True
B. False
Answer» C.
9.

An has a phase shift of 180° from input to output.

A. True
B. False
Answer» B. False
10.

The amplifier circuit has a fixed voltage gain of approximately 10.

A. True
B. False
Answer» C.
11.

An inverting amplifier has a phase shift of 180° from input to output.

A. True
B. False
Answer» B. False
12.

It takes 4 s for the output voltage of an op-amp to rise from –14 V to +14 V. The slew rate of this op-amp is 3.5 V/s.

A. True
B. False
Answer» C.
13.

If ground is applied to the (+) terminal of an inverting op-amp, the (–) terminal will:

A. not need an input resistor
B. be virtual ground
C. have high reverse current
D. not invert the signal
Answer» C. have high reverse current
14.

In an open-loop op-amp circuit, whenever the inverting input (–) is negative relative to the noninverting input (+), the output will:

A. swing negative
B. close the loop
C. be balanced
D. swing positive
Answer» E.
15.

Ideally, the value of the CMRR is ________. Practically, the ________ the value of CMRR, the better the circuit operation.

A. zero, smaller
B. infinite, larger
C. zero, larger
D. infinite, smaller
Answer» C. zero, larger
16.

The common-mode rejection ratio (CMRR) is defined by ________.

A. Ad / Ac
B. Ac / Ad
C. Ad × Ac
D. Ad + Ac
Answer» B. Ac / Ad
17.

When both input signals are the same, a common signal element due to the two inputs can be defined as the ________ of the two signals.

A. difference
B. sum
C. average of the sum
D. product
Answer» D. product
18.

The ratio of the unity-gain frequency to the cutoff frequency is numerically equal to the level of ________.

A. CMRR
B. common-mode gain
C. closed-loop gain
D. open-loop gain
Answer» D. open-loop gain
19.

The output offset voltage is determined by ________.

A. the input offset voltage and input offset current
B. the closed-loop gain
C. both the input offset voltage and the closed-loop gain
D. None of the above
Answer» B. the closed-loop gain
20.

Inverting amplifier connection is more widely used because it has ________.

A. higher gain
B. better frequency stability
C. unit gain
D. None of the above
Answer» E.
21.

As the frequency increases, the input impedance of an op-amp ________ and the output impedance ________.

A. increases, increases
B. increases, decreases
C. decreases, decreases
D. decreases, increases
Answer» D. decreases, increases
22.

As the supply voltage increases, the voltage gain of the circuit ________ and the power consumption ________.

A. increases, increases
B. increases, decreases
C. decreases, decreases
D. decreases, increases
Answer» B. increases, decreases
23.

The maximum frequency at which an op-amp may operate depends on the ________.

A. bandwidth (BW)
B. slew rate (SR)
C. unity-gain bandwidth
D. All of the above
Answer» E.
24.

________ is the unit for the slew rate, SR.

A. V/ms
B. ms/V
C. V
D. V/s
Answer» B. ms/V
25.

The feedback component of an integrator is a(n) ________.

A. resistor
B. capacitor
C. inductor
D. diode
Answer» C. inductor
26.

The ________ amplifier is the most widely used constant-gain amplifier circuit.

A. inverting
B. noninverting
C. differential
D. None of the above
Answer» B. noninverting
27.

An ideal op-amp circuit has ________input impedance, ________ output impedance, and ________ voltage gain.

A. zero, infinite, infinite
B. infinite, zero, zero
C. zero, zero, infinite
D. infinite, zero, infinite
Answer» E.
28.

A ________ differential amplifier is particularly well suited for battery operation due to its low power consumption.

A. BiFET
B. BiMOS
C. CMOS
D. BJT
Answer» D. BJT
29.

An IC unit containing a differential amplifier built using opposite-type MOSFET transistors is referred to as a ________ circuit.

A. CMOS
B. BiFET
C. BiMOS
D. None of the above
Answer» B. BiFET
30.

An IC unit containing a differential amplifier built using both bipolar and FET transistors is referred to as a ________ circuit.

A. CMOS
B. BiFET
C. BiMOS
D. None of the above
Answer» C. BiMOS
31.

If the same input is applied to both inputs, the operation is called ________.

A. double-ended
B. single-ended
C. common-mode
D. All of the above
Answer» D. All of the above
32.

The main feature of the differential amplifier is the ________ gain when opposite signals are applied to the inputs as compared to the ________ gain resulting from common inputs.

A. very large, large
B. very small, large
C. very small, very large
D. very large, very small
Answer» E.
33.

If two opposite-polarity input signals are applied, the operation is referred to as ________.

A. double-ended
B. single-ended
C. common-mode
D. All of the above
Answer» B. single-ended
34.

In a differential amplifier circuit, if an input signal is applied to either input with the other input connected to ground, the operation is referred to as ________.

A. double-ended
B. single-ended
C. common-mode
D. All of the above
Answer» C. common-mode
35.

In a differential connection, the signals that are opposite at the inputs are ________ amplified, and those that are common to the two inputs are ________ amplified.

A. slightly, slightly
B. slightly, highly
C. highly, highly
D. highly, slightly
Answer» E.
36.

An input applied to either input terminal will result in ________.

A. outputs from both output terminals, which have opposite polarities
B. outputs from both output terminals, which have the same polarities
C. a single output from one of the output terminals
D. None of the above
Answer» B. outputs from both output terminals, which have the same polarities
37.

In double-ended (differential) input operation, ________.

A. an input is applied between the two input terminals
B. two separate signals are applied to the input terminals
C. either an input is applied between the two input terminals or two separate signals are applied to the input terminals
D. None of the above
Answer» D. None of the above
38.

The output signal of an op-amp is ________ out of phase with its input signal connected to the inverting input terminal.

A.
B. 90º
C. 180º
D. 270º
Answer» D. 270º
39.

An operational amplifier has a ________ input impedance and a ________ output impedance.

A. high, low
B. high, high
C. low, low
D. low, high
Answer» B. high, high
40.

An operational amplifier is a ________ gain and ________ bandwidth differential amplifier.

A. very low, narrow
B. low, wide
C. medium, narrow
D. very high, wide
Answer» E.
41.

Calculate the output impedance of an inverting op-amp using the 741 op-amp (ro = 75 , AOL = 200 V/mV) if R1 = 100 and Rf = 1 k.

A. 0.011
B. 0.00375
C. 0.0375
D. 0.375
Answer» C. 0.0375
42.

Calculate the output voltage if R1 = R2 = R3 = 100 , Rf = 1 k, and V1 = V2 = V3 = 50 mV.

A. –1.5 V
B. 1.5 V
C. 0.5 V
D. –0.5 V
Answer» B. 1.5 V
43.

Calculate the input voltage if R1 = 100 , Rf = 1 k, and Vout = 550 mV.

A. –50 mV
B. –5 mV
C. 550 mV
D. 50 mV
Answer» E.
44.

Calculate the overall voltage gain of the circuit if R1 = 100 and Rf = 1 k.

A. –1
B. –10
C. 11
D. 9
Answer» D. 9
45.

Calculate the overall voltage gain of the circuit if R1 = 100 and Rf = 1 k.

A. –1
B. –10
C. 11
D. 9
Answer» C. 11
46.

If Rf = R1, the voltage gain is ________.

A. 1
B. –1
C. 10
D. very small
Answer» C. 10
47.

When the open-loop gain of an op-amp is reduced by negative feedback, the bandwidth is increased.

A. True
B. False
Answer» B. False
48.

Open-loop gain is always smaller than closed-loop gain.

A. True
B. False
Answer» C.
49.

Negative feedback decreases the bandwidth and increases the voltage gain.

A. True
B. False
Answer» C.
50.

Closed-loop gain is the gain with negative feedback.

A. True
B. False
Answer» B. False