MCQ in Electronic Circuits Part 15 | ECE Board Exam

(Last Updated On: July 27, 2022)

This is the Multiples Choice Questions Part 15 of the Series in Electronic Circuit (Audio/RF), Analysis and Design as one of the Electronics Engineering topic. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Exam Questions in Electronics Engineering field, Electronics Books, Journals and other Electronics References.

MCQ Topic Outline included in ECE Board Exam Syllabi

• MCQ in Amplifiers
• MCQ in Oscillators
• MCQ in Rectifier
• MCQ in Filters
• MCQ in Voltage Regulation

Continue Practice Exam Test Questions Part 15 of the Series

⇐ MCQ in Electronic Circuits Part 14 | ECE Board Exam

Choose the letter of the best answer in each questions.

701. Consider a Zener diode with a slope resistance of 10 Ω in series with a 90 Ω resistor fed from a dc supply containing a ripple voltage of 20 mV peak-to-peak. Compute for the ripple voltage in load

A. 1 mv p-p

B. 2 mv p-p

C. 1 v p-p

D. 6mv p-p

702. The ______ of a common collector configuration is unity

A. voltage gain

B. current gain

C. power gain

D. input impedance

703. Transmit time is the time taken by the electrons on holes to pass from ______.

A. emitter to collector

B. collector to emitter

C. base to emitter

D. base to collector

704. Which amplifier is commonly used as a frequency multiplier?

A. class A

B. class B

C. class C

D. all of the above

705. A class A amplifier has a voltage gain of 30 and a current gain of What is the power gain?

A. 30

B. 25

C. 1.2

D. 750

706. You have an application for a power amplifier to operate on FM radio frequencies. The most likely choice would be a ______ amplifier.

A. class A

B. class B

C. class C

D. class AB

707. A class A amplifier with R_C = 3.3 kΩ and R_E = 1.2 kΩ has a V_CC = 20 V. Find I_C(sat).

A. 4.4 ma

B. 6.1 ma

C. 16.7 ma

D. 20 ma

708. A class C amplifier has a tank circuit in the output. The amplifier is conducting only 28°. The output voltage is ____.

A. 0 v.

B. a dc value equal to vcc.

C. a sine wave.

D. a square wave with a frequency determined by the tank.

709. In practice, the efficiency of a capacitively coupled class A amplifier is about ___%.

A. 25

B. 40

C. 70

D. 10

710. The Q-point is at cutoff for class operation.

A. a

B. b

C. c

D. ab

711. Class amplifiers are normally operated in a push-pull configuration in order to produce an output that is a replica of the input.

A. a

B. b

C. c

D. ab

712. The maximum efficiency of a class B amplifier is percent.

A. 50

B. 25

C. 70

D. 79

713. A class amplifier is biased slightly above cutoff and operates in the linear region for slightly more than 180° of the input cycle.

A. a

B. b

C. c

D. ab

714. Which class of amplifier operates in the linear region for only a small part of the input cycle?

A. a

B. b

C. c

D. ab

715. The principal advantage(s) of MOSFETs over BJTs is (are)

A. their biasing networks are simpler.

B. their drive requirements are simpler.

C. they can be connected in parallel for added drive capability.

D. all of the above

716. The principal advantage(s) of BJTs over MOSFETs is (are) that

A. voltage drop across the transistor is important.

B. they are not as prone to esd.

C. both of the above

D. none of the above

717. The class amplifier is biased below cutoff.

A. a

B. ab

C. b

D. c

718. For Class-B operation, the collector current flows for

A. the whole cycle

B. half the cycle

C. less than half a cycle

D. less than a quarter of a cycle

719. Transformer coupling is an example of

A. direct coupling

B. ac coupling

C. dc coupling

D. impedance coupling

720. Class-C amplifiers are almost always

A. transformer- coupled between stages

B. operated at audio frequencies

C. tuned rf amplifiers

D. wideband

721. Heat sinks reduce the

A. transistor power

B. ambient temperature

C. junction temperature

D. collector current

722. Which type of power amplifier is biased for operation at less than 180° of the cycle?

A. class a

B. class b or ab

C. class c

D. class d

723. What is the maximum efficiency of a class A circuit with a direct or series-fed load connection?

A. 90%

B. 78.50%

C. 50%

D. 25%

724. The Q-point is at cutoff for class operation.

A. a

B. b

C. c

D. ab

725. Which of the following is (are) power amplifiers?

A. class a

B. class b or ab

C. class c or d

D. all of the above

726. The output of a class-B amplifier

A. is distortion free

B. consists of positive half cycle only

C. is like the output of a full wave rectifier

D. comprises short duration current pulses

727. Crossover distortion occurs in amplifiers.

A. push-pull

B. class a

C. class b

D. class ab

728. The main use of a class C amplifier is

A. as an RF amplifier

B. as stereo amplifier

C. in communication sound equipment

D. as distortion generator

729. The decibel is a measure of

A. power

B. voltage

C. current

D. sound level

730. The output stage of a multistage amplifier is also called

A. mixer stage

B. power stage

C. detector stage

D. f stage

731. coupling is generally employed in power amplifiers

A. transformer

B. rc

C. direct

D. impedance

732. The maximum efficiency of resistance loaded class A power amplifier is

A. 5%

B. 50%

C. 30%

D. 25%

733. Class power amplifier has the highest collector efficiency

A. c

B. a

C. b

D. ab

734. Power amplifiers handle signals compare to voltage amplifiers.

A. small

B. very small

C. large

D. none of the above

735. In class B operation, at what fraction of V_CC should the level of VL(p) be to achieve the maximum power dissipated by the output transistor?

A. 0.5

B. 0.636

C. 0.707

D. 1

736. In class A operation, the operating point is generally located ______ of the d.c. load line.

A. at cut off point

B. at the middle

C. at saturation point

D. none of the above

737. The output transformer used in a power amplifier is a ______ transformer.

A. 1:1 ratio

B. step-up

C. step-down

D. none of the above

738. Power amplifiers primarily provide sufficient power to an output load, typically from to .

A. a few kw, tens of kw

B. 500 w, 1 kw

C. 100 w, 500 w

D. a few w, tens of w

739. The main feature(s) of a large-signal amplifier is (are) the

A. circuit’s power efficiency

B. maximum amount of power that the circuit is capable of handling

C. impedance matching to the output

D. all of the above

740. In power amplifiers, the output signal varies for a full 360° of the cycle.

A. class a

B. class b or ab

C. class c

D. class d

741. In class B power amplifiers, the output signal varies for of the cycle.

A. 360°

B. 180°

C. between 180° and 360°

D. less than 180°

742. amplifiers have the highest overall efficiency.

A. class a

B. class b or ab

C. class c

D. class d

743. Class D operation can achieve power efficiency of over .

A. 90%

B. 78.50%

C. 50%

D. 25%

744. The beta of a power transistor is generally .

A. more than 200

B. 100 to 200

C. less than 100

D. none of these

745. A form of class A amplifier having maximum efficiency of ____ uses a transformer to couple the output signal to the load.

A. 90%

B. 78.50%

C. 50%

D. 25%

746. The reflected impedance seen from one side of the transformer to the other side is .

A. n1/n2

B. (n1/n2)²

C. (n1/n2)1/3

D. n1× n2

747. In a class A transformer-coupled power amplifier, winding resistance of the transformer determine(s) the dc load line for the circuit.

A. the ac

B. the dc

C. both the ac and dc

D. neither the ac nor dc

748. The slope of the ac load line in the class A transformer-coupled transistor is .

A. –1/R_L (load resistor)

B. 1/(a²R_L)

C. –1/(a²R_L)

D. 1/R_L

749. The amount of power dissipated by the transistor is the of that drawn from the dc supply (set by the bias point) and the amount delivered to the ac load.

A. product

B. difference

C. average

D. none of these

750. A class A amplifier dissipates power when the load is drawing maximum power from the circuit.

A. the least

B. about the same

C. the most

D. none of the above

Questions and Answers in Electronic Circuits

Following is the list of practice exam test questions in this brand new series:

Complete List of MCQ in Electronics Engineering per topic