Study mode · no timer

A.C. Fundamentals, Circuits and Circuit Theory

Study 109 Electrical Engineering MCQs with correct answers and explanations.

Answers and explanations are always visible Take this test

11Electrical EngineeringMedium

At very low frequencies a series R-C circuit behaves as almost purely________?

Aresistive

Bcapacitive

Cinductive

Dnone of the above

Correct answer

B. capacitive

Explanation

The correct answer is capacitive.

12Electrical EngineeringMedium

A heater is rated as 230 V, 10 kW, A.C. The value 230 V refers to________?

Aaverage voltage

Br.m.s. voltage

Cnone of the above

Dpeak voltage

Correct answer

B. r.m.s. voltage

Explanation

The correct answer is r.m.s. voltage.

13Electrical EngineeringMedium

In a purely inductive circuit________?

Aactual power is zero

Breactive power is zero

Cnone of above is zero

Dapparent power is zero

Correct answer

A. actual power is zero

Explanation

The correct answer is actual power is zero.

14Electrical EngineeringMedium

In an A.C. circuit power is dissipated in________?

Acapacitance only

Bnone of the above

Cresistance only

Dinductance only

Correct answer

C. resistance only

Explanation

The correct answer is resistance only.

15Electrical EngineeringMedium

The effective resistance of an iron-cored choke working on ordinary supply frequency is more than its true resistance because of________?

Airon loss in core

Bincrease in temperature

Ccapacitive effect between adjacent coil turns

Dskin effect

Correct answer

A. iron loss in core

Explanation

The correct answer is iron loss in core.

16Electrical EngineeringMedium

Power factor of an inductive circuit is usually improved by connecting capacitor to it in________?

Aseries

Beither A. or (b)

Cnone of the above

Dparallel

Correct answer

D. parallel

Explanation

The correct answer is parallel.

17Electrical EngineeringMedium

For a frequency of 200 Hz, the time period will be________?

A0.5 s

B0.0005 s

C0.05 s

D0.005 s

Correct answer

D. 0.005 s

Explanation

The correct answer is 0.005 s.

18Electrical EngineeringMedium

Which of the following waves has the highest value of peak factor ________?

ASquare wave

BHalf wave rectified sine wave

CTriangular wave

DSine wave

Correct answer

B. Half wave rectified sine wave

Explanation

The correct answer is Half wave rectified sine wave.

19Electrical EngineeringMedium

Power factor of the following circuit will be unity

Aboth A. and B.

Bcapacitance

Cinductance

Dresistance

Correct answer

D. resistance

Explanation

The correct answer is resistance.

20Electrical EngineeringMedium

Wire-wound resistors are unsuitable for use at high frequencies because they________?

Aare likely to melt under excessive eddy current heat

Bcreate more electrical noise

Cexhibit unwanted inductive and capacitive effects

Dconsume more power

Correct answer

C. exhibit unwanted inductive and capacitive effects

Explanation

The correct answer is exhibit unwanted inductive and capacitive effects.

Wire-wound resistors are unsuitable for use at high frequencies because they________?

Aare likely to melt under excessive eddy current heat

Bcreate more electrical noise

Cexhibit unwanted inductive and capacitive effects

Dconsume more power

Correct answer

C. exhibit unwanted inductive and capacitive effects

Explanation

The correct answer is exhibit unwanted inductive and capacitive effects.