Explore topic-wise MCQs in Electronics.

This section includes 44 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 ___ oscillator takes advantage of the .

A. crystal
B. Hartley
C. Colpitts
Answer» B. Hartley
2.

In order to sustain oscillations in a feedback oscillator, the gain should be _________ so the product of × equals_______.

A. reduced, one
B. reduced, less than one
C. increased, more than one
D. increased, much greater than one
Answer» B. reduced, less than one
3.

approximately equals _______ when a transistor is in saturation.

A. 0.2 V
B. 0.7 V
Answer» D.
4.

The power gain () of any transistor amplifier circuit equals the ___________.

A. current gain squared
B. current gain times the voltage gain
C. voltage gain times the output resistance
D. current gain plus the voltage gain
Answer» C. voltage gain times the output resistance
5.

If the drain, source, and channel of a MOSFET are all a -type material, and it operates in both modes, this is an -channel D-MOSFET.

A. True
B. False
Answer» C.
6.

In an -type JFET, current will flow when a positive voltage is applied to the drain and a negative voltage is applied to the source.

A. True
B. False
Answer» B. False
7.

The of a BJT is the ratio of collector current to emitter current.

A. True
B. False
Answer» C.
8.

A source follower has a voltage gain () of

A. =
B. =
Answer» D.
9.

The signal voltage gain of an amplifier, , is defined as:

A. =
B. ×
Answer» D.
10.

The formula used to calculate the approximate ac resistance of the base-emitter diode () is

A.
B. 25 mV ×
Answer» B. 25 mV ×
11.

In order to sustain oscillations in a feedback oscillator, the gain should be _________ so the product of Av × B equals_______.

A. reduced, one
B. reduced, less than one
C. increased, more than one
D. increased, much greater than one
Answer» B. reduced, less than one
12.

The ac input resistance (Rin) of a voltage-divider biased common-emitter amplifier consists of ____________.

A. [A].
B. [B].
C. [C].
D. [D].
Answer» C. [C].
13.

An essential requirement of a feedback oscillator is a phase shift around the feedback loop of 360°.

A. True
B. False
Answer» B. False
14.

A source follower has a voltage gain (Av) of

A. AV = gmRd
B. AV = gmRS
C. [C].
D. [D].
Answer» D. [D].
15.

The formula used to calculate the approximate ac resistance of the base-emitter diode (re) is

A. [A].
B. re 25 mV × IC
C. [C].
D. [D].
Answer» B. re 25 mV × IC
16.

The signal voltage gain of an amplifier, Av, is defined as:

A. [A].
B. Av = IC × RC
C. [C].
D. [D].
Answer» D. [D].
17.

The gain of a BJT is called _______ and the gain of a JFET is called _______.

A. beta, alpha
B. transconductance, beta
C. beta, transconductance
D. transconductance, transconductance
Answer» D. transconductance, transconductance
18.

A decrease in base current of a CE amplifier causes the voltage measured between the emitter and the collector to increase.

A. 1
B.
Answer» B.
19.

Changing ________ can control the voltage gain of a common-source amplifier.

A. the input voltage
B. gm
C. VDD
D. RS
Answer» C. VDD
20.

In an n-type JFET, current will flow when a positive voltage is applied to the drain and a negative voltage is applied to the source.

A. 1
B.
Answer» B.
21.

Removing a bypass capacitor from a common-emitter amplifier circuit will _________ voltage gain and ________ input resistance.

A. increase, decrease
B. decrease, increase
C. decrease, decrease
D. increase, increase
Answer» C. decrease, decrease
22.

An essential requirement of a feedback oscillator is a phase shift around the feedback loop of 360°.

A. 1
B.
Answer» B.
23.

The collector current in a class A amplifier flows for ________ of the ac input signal.

A. < 180°
B. 180°
C. < 360°
D. 360°
Answer» E.
24.

The depletion-mode MOSFET

A. can operate with only positive gate voltages
B. can operate with only negative gate voltages
C. cannot operate in the ohmic region
D. can operate with positive as well as negative gate voltages
Answer» E.
25.

The beta of a BJT is the ratio of collector current to emitter current.

A. 1
B.
Answer» C.
26.

A(n) ___ has a conductive channel only when it is biased properly.

A. p-channel JFET
B. n-channel D-MOSFET
C. p-channel D-MOSFET
D. n-channel E-MOSFET
Answer» E.
27.

The maximum peak-to-peak output voltage in the given circuit is 15 V.

A. 1
B.
Answer» C.
28.

Which of the following conditions are needed to properly bias an npn transistor amplifier?

A. Forward bias the base/emitter junction and reverse bias the base/collector junction.
B. Forward bias the collector/base junction and reverse bias the emitter/base junction.
C. Apply a positive voltage on the n-type material and a negative voltage on the p-type material.
D. Apply a large voltage on the base.
Answer» B. Forward bias the collector/base junction and reverse bias the emitter/base junction.
29.

The ___ oscillator takes advantage of the piezoelectric effect.

A. crystal
B. Hartley
C. Colpitts
D. RC
Answer» B. Hartley
30.

The power gain (Ap) of any transistor amplifier circuit equals the ___________.

A. current gain squared
B. current gain times the voltage gain
C. voltage gain times the output resistance
D. current gain plus the voltage gain
Answer» C. voltage gain times the output resistance
31.

Three different points are shown on a dc load line. The upper point represents the

A. minimum current gain
B. quiescent point
C. saturation point
D. cutoff point
Answer» D. cutoff point
32.

In a class B push-pull amplifier, the transistors are biased slightly above cutoff to avoid

A. crossover distortion
B. unusually high efficiency
C. negative feedback
D. a low input impedance
Answer» B. unusually high efficiency
33.

A certain amplifier has a voltage gain of 210. That gain expressed in decibels is 46.4 dB.

A. 1
B.
C. 1
D.
Answer» B.
34.

VCE approximately equals _______ when a transistor is in saturation.

A. VCC
B. VB
C. 0.2 V
D. 0.7 V
Answer» D. 0.7 V
35.

Base currents are usually small because of the physical construction of the thin and lightly doped base.

A. 1
B.
Answer» B.
36.

A practical CE amplifier has the input on the base and the output taken off the emitter.

A. 1
B.
Answer» C.
37.

To get a negative gate-source voltage in a self-biased JFET circuit, you must use a

A. voltage divider
B. source resistor
C. ground
D. negative gate supply voltage
Answer» C. ground
38.

In order to sustain oscillations in a feedback oscillator, the gain should be _________ so the product of Av √ó B equals_______.

A. reduced, one
B. reduced, less than one
C. increased, more than one
D. increased, much greater than one
Answer» B. reduced, less than one
39.

In order for feedback oscillators to have any practical value, the gain has to be

A. < 1
B. self-adjusting
C. stabilized
D. nonlinear
Answer» C. stabilized
40.

The capacitor that produces an ac ground is called a(n)

A. coupling capacitor
B. dc open
C. bypass capacitor
D. ac open
Answer» D. ac open
41.

Often a common-collector will be the last stage before the load; the main function of this stage is to

A. provide voltage gain
B. buffer the voltage amplifiers from the low-resistance load
C. provide phase inversion
D. provide a high-frequency path to improve the frequency response
Answer» C. provide phase inversion
42.

The gate-source junction of a JFET must be ________ for proper linear operation.

A. forward-biased
B. reverse-biased
C. either forward-biased or reverse-biased
D. neutral
Answer» C. either forward-biased or reverse-biased
43.

If the drain, source, and channel of a MOSFET are all a p-type material, and it operates in both modes, this is an n-channel D-MOSFET.

A. 1
B.
C. 1
D.
Answer» C. 1
44.

The primary function of the bias circuit is to

A. hold the circuit stable at VCC
B. hold the circuit stable at vin
C. ensure proper gain is achieved
D. hold the circuit stable at the designed Q-point
Answer» E.