Electrical Engineering Mcqs Practice Test

Question 1

Time constant of a circuit is the time in seconds taken after the application of voltage to each___________?

Accepted Answer

C. 63% of maximum value

Question 2

The safest value of current the human body can carry for more than 3 second is_________?

Accepted Answer

B. 9 mA

Question 3

If resistance is 20 Q. and inductance is 27 in a R-L series circuit, then time constant of this circuit will be________?

Accepted Answer

B. 0.1 s

Question 4

In a R-L-C circuit_________?

Accepted Answer

E. all above are correct

Question 5

If a sinusoidal wave has frequency of 50 Hz with 30 A r.m.s. current which of the following equation represents this wave_________ ?

Accepted Answer

A. 42.42 sin 3141

Question 6

Which of the following coil will have large resonant frequency __________?

Accepted Answer

C. A coil with large distributed capacitance

Question 7

In an AC. circuit, a low value of kVAR compared with kW indicates_________?

Accepted Answer

B. high power factor

Question 8

The input of an A.C. circuit having power factor of 0.8 lagging is 40 kVA The power drawn by the circuit is__________?

Accepted Answer

C. 32 kW

Question 9

A pure inductance connected across 250 V, 50 Hz supply consumes 100 W. This consumption can be attributed to_________?

Accepted Answer

D. the statement given is false

Question 10

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

Accepted Answer

A. iron loss in core

Question 11

The ratio of active power to apparent power is known as factor__________?

Accepted Answer

C. power

Question 12

The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is_________?

Accepted Answer

B. 6 kVAR

Question 13

A parallel AC. circuit in resonance will__________?

Accepted Answer

B. have a high impedance

Question 14

In AC. circuits, laminated iron is invariably used in order to__________?

Accepted Answer

A. reduce eddy current loss

Question 15

All definitions of power factor of a series R-L-C circuit are correct except__________?

Accepted Answer

A. ratio of net reactance and impedance

Question 16

The purpose of a parallel circuit resonance is to magnify________?

Accepted Answer

B. voltage

Question 17

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

Accepted Answer

D. exhibit unwanted inductive and capacitive effects

Question 18

Which of the following statements pertains to resistors only _____________?

Accepted Answer

A. can dissipate considerable amount of power

Question 19

Aphasoris________?

Accepted Answer

A. a line which represents the magnitude and phase of an alternating quantity

Question 20

Capacitive susceptance is a measure of__________?

Accepted Answer

C. a purely capacitive circuit’s ability to pass current