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.

101.

The voltage required to force the differential output to zero is called _______.

A. input-offset current
B. input-offset voltage
C. input bias current
D. slew rate voltage
Answer» C. input bias current
102.

If an input signal is applied to the inverting input of an op-amp with the noninverting input grounded, the output signal would be opposite in polarity to the input.

A. 1
B.
Answer» B.
103.

Operational amplifiers (op-amps) use internal capacitive coupling between stages.

A. 1
B.
Answer» C.
104.

The 555 timer can be connected to operate a(n) ___________.

A. astable multivibrator
B. bistable multivibrator
C. monostable multivibrator
D. astable multivibrator and a monostable multivibrator
Answer» E.
105.

The ideal output impedance for an operational amplifier is 0 .

A. 1
B.
Answer» B.
106.

A voltage-follower op-amp has the output connected directly to the inverting input.

A. 1
B.
Answer» B.
107.

A virtual ground is a(n) ______ ground because this point is at zero volts.

A. ordinary
B. voltage
C. chassis
D. earth
Answer» C. chassis
108.

If the input to a comparator is a sine wave, the output is a(n) _________.

A. ramp voltage
B. sine wave
C. sawtooth wave
D. rectangular wave
Answer» E.
109.

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

A. 1
B.
Answer» B.
110.

The frequency of a crystal is dependent on how much voltage is applied to activate it.

A. 1
B.
Answer» C.
111.

The input impedance is ______ for the amplifier in the given circuit. The data sheet values are Zin = 3 M, Zout = 80 , and Aol = 250,000.

A. 4.7 k
B. 22.7 k
C. 3 M
D. 68.6 k
Answer» B. 22.7 k
112.

______ is NOT a characteristic of an ideal op-amp.

A. Infinite voltage gain
B. Minimum bandwidth
C. Infinite input impedance
D. Zero output impedance
Answer» C. Infinite input impedance
113.

An astable multivibrator has two states.

A. 1
B.
Answer» B.
114.

The common-mode rejection ratio (CMMR) is the ratio of _____ to ______.

A. the differential voltage gain, the common-mode voltage gain
B. the differential power gain, the common-mode power gain
C. the ideal voltage gain, the actual voltage gain
D. signal voltage, noise voltage
Answer» B. the differential power gain, the common-mode power gain
115.

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. 1
B.
Answer» C.
116.

A 555 timer can be configured as an astable multivibrator.

A. 1
B.
Answer» B.
117.

The feedback resistor has a value of ______ in the given circuit

A. 2 k
B. 10.5 k
C. 21 k
D. 40 k
Answer» E.
118.

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

A. 1
B.
Answer» C.
119.

An open feedback resistor in an inverting or noninverting op-amp circuit can cause severe clipping of the output signal.

A. 1
B.
Answer» B.
120.

Crystal oscillator circuits have a very low Q.

A. 1
B.
Answer» C.
121.

The resistors Rf and Ri 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
122.

In a common-mode input to an op-amp, both inputs are connected to the same signal source.

A. 1
B.
Answer» B.
123.

If an input signal is applied to the inverting input of an op-amp with the noninverting input grounded, the output signal would be opposite in polarity with the input.

A. 1
B.
Answer» B.
124.

An oscillator whose frequency can be controlled by an input "control voltage" is called a(n) ______ .

A. PLL
B. Schmitt trigger
C. VCO
D. S-R latch
Answer» D. S-R latch
125.

An S-R flip-flop is an example of a bistable multivibrator circuit.

A. 1
B.
Answer» B.
126.

What starts a free-running multivibrator?

A. a trigger
B. an input signal
C. an external circuit
D. nothing
Answer» E.
127.

In order for an output to swing above and below a zero reference, the op-amp circuit requires:

A. a resistive feedback network
B. zero offset
C. a wide bandwidth
D. a negative and positive supply
Answer» E.
128.

What is the output voltage?

A. 15 V
B. 5 V
C. –5 V
D. –15 V
Answer» D. ‚Äì15 V
129.

An astable multivibrator is also known as a:

A. one-shot multivibrator
B. free-running multivibrator
C. bistable multivibrator
D. monostable multivibrator
Answer» C. bistable multivibrator
130.

An operational amplifier contains a differential amplifier, a voltage amplifier, and an output amplifier.

A. 1
B.
C. 1
D.
Answer» B.
131.

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

A. Ri
B. Rf + Ri
C. ‚àû
D. Rf – Ri
Answer» B. Rf + Ri
132.

What is the frequency of this 555 astable multivibrator?

A. 278 Hz
B. 178 Hz
C. 78 Hz
D. 8 Hz
Answer» C. 78 Hz
133.

This circuit is a differentiator.

A. 1
B.
C. 1
D.
Answer» B.
134.

Common-mode signals have _____.

A. the same amplitude
B. the same phase
C. the same frequency
D. All of the above
Answer» E.
135.

The given circuit is ___.

A. an inverting amplifier
B. a noninverting amplifier
C. a voltage follower
D. a differential amplifier
Answer» C. a voltage follower
136.

What is the difference between common-mode and differential-mode input signals?

A. phase relationship
B. voltage
C. current
D. apparent power
Answer» B. voltage
137.

The Schmitt trigger is a two-state device that is used for:

A. pulse shaping
B. peak detection
C. input noise rejection
D. filtering
Answer» B. peak detection
138.

When a capacitor is used in place of a resistor in an op-amp network, its placement determines:

A. open- or closed-loop gain
B. integration or differentiation
C. saturation or cutoff
D. addition or subtraction
Answer» C. saturation or cutoff
139.

A circuit that has an output equal to the algebraic sum of the inputs is called a(n) ______ .

A. integrator amplifier
B. summing amplifier
C. differential amplifier
D. voltage multiplier
Answer» C. differential amplifier
140.

An ideal amplifier should have:

A. high input current
B. zero offset
C. high output impedance
D. moderate gain
Answer» C. high output impedance
141.

What is the output waveform of the circuit?

A. sine wave
B. square wave
C. sawtooth wave
D. triangle wave
Answer» C. sawtooth wave
142.

A virtual ground is a ground for current, but not for voltage.

A. 1
B.
C. 1
D.
Answer» C. 1
143.

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

A. the ratio of the input resistance to the feedback resistance
B. the open-loop voltage gain Aol
C. the feedback resistance divided by the input resistance
D. the input resistance
Answer» D. the input resistance
144.

With negative feedback, the returning signal:

A. aids the input signal
B. is proportional to output current
C. opposes the input signal
D. is proportional to differential voltage gain
Answer» D. is proportional to differential voltage gain
145.

How many logic states does an S-R flip-flop have?

A. 2
B. 3
C. 4
D. 5
Answer» D. 5
146.

If the frequency of an astable multivibrator is 54.86 kHz then its period is 1.82 s.

A. 1
B.
C. 1
D.
Answer» C. 1
147.

This circuit is operating in a closed-loop mode.

A. 1
B.
Answer» C.
148.

If the feedback/input resistor ratio of a feedback amplifier is 4.6 with 1.7 V applied to the noninverting input, what is the output voltage value?

A. 7.82 V
B. saturation
C. cutoff
D. 9.52 V
Answer» E.
149.

The voltage gain of the amplifier in the given circuit would increase if ______.

A. the feedback resistor was decreased in value
B. the input voltage was increased
C. the input resistor was increased in value
D. None of the above
Answer» E.
150.

A circuit whose output is proportional to the difference between the input signals is considered to be which type of amplifier?

A. common-mode
B. darlington
C. differential
D. operational
Answer» D. operational