Electrical Engineering Mcqs Practice Test

Question 1

The power factor of a D.C. circuit is always__________?

Accepted Answer

B. unity

Question 2

In a pure inductive circuit if the supply frequency is reduced to 1/2, the current will__________?

Accepted Answer

B. be doubled

Question 3

In a pure capacitive circuit if the supply frequency is reduced to 1/2, the current will__________?

Accepted Answer

A. be reduced by half

Question 4

An A.C. voltage is impressed across a pure resistance of 3.5 ohms in parallel with a pure inductance of impedance of 3.5 ohms?

Accepted Answer

C. both resistance and inductance carry equal currents

Question 5

The product of apparent power and cosine of the phase angle between circuit voltage and current is

Accepted Answer

A. true power

Question 6

A pure capacitor connected across an A.C. voltage consumed 50 W. This is due to________?

Accepted Answer

D. the statement is incorrect

Question 7

When an alternating current passes through an ohmic resistance the electrical power converted into heat is__________?

Accepted Answer

B. true power

Question 8

In each of the three coils of a three phase generator, an alternating voltage having an r.m.s. value of 220 V is induced. Which of the following values is indicated by the voltmeters ______?

Accepted Answer

A. 220 V

Question 9

The power factor at resonance in R-L- C parallel circuit is________?

Accepted Answer

D. unity

Question 10

In a pure inductive circuit___________?

Accepted Answer

B. the current lags behind the voltage by 90°

Question 11

In the case of an unsymmetrical alternating current the average value must always be taken over__________?

Accepted Answer

D. the whole cycle

Question 12

The transient currents are associated with the____________?

Accepted Answer

A. changes in the stored energy in the inductors and capacitor

Question 13

In a pure resistive circuit__________?

Accepted Answer

D. current is in phase with the voltage

Question 14

In a circuit containing R, L and C, power loss can take place in____________?

Accepted Answer

C. R only

Question 15

The r.m.s. value of alternating current is given by steady (D.C.) current which when flowing through a given circuit for a given time produces__________?

Accepted Answer

B. the same heat as produced by A.C. when flowing through the same circuit

Question 16

The time constant of the capacitance circuit is defined as the time during which voltage________?

Accepted Answer

C. rises to 63.2% of its final steady value

Question 17

The square waveform of current has following relation between r.m.s. value and average value?

Accepted Answer

A. r.m.s. value is equal to average value

Question 18

In a loss-free R-L-C circuit the transient current is__________?

Accepted Answer

C. sinusoidal

Question 19

Power factor of the system is kept high__________?

Accepted Answer

D. due to all above reasons

Question 20

Power factor of the following circuit will be zero__________?

Accepted Answer

D. both B. and C.