A.C Fundamentals, Circuits and Circuit Theory MCQs

Question 1

Which of the following refers to a parallel circuit?

Accepted Answer

The current through any one element is less than the source current

Answer

The current through each element is same

Answer

The voltage across element is in proportion to it's resistance value

Answer

The equivalent resistance is greater than any one of the resistors

Question 2

In any A.C. circuit always

Accepted Answer

Apparent power is more than actual power

Answer

Reactive power is more than apparent power

Answer

Actual power is more than reactive power

Answer

Reactive power is more than actual power

Question 3

The transient currents are associated with the

Accepted Answer

Changes in the stored energy in the inductors and capacitors

Answer

Impedance of the circuit

Answer

Applied voltage to the circuit

Answer

Resistance of the circuit

Question 4

The inductance of a coil can be increased by

Accepted Answer

Choosing core material having high relative permeability

Answer

Increasing core length

Answer

Decreasing the number of turns

Answer

Decreasing the diameter of the former

Question 5

Power factor of an electrical circuit is equal to

Accepted Answer

All above

Answer

$$\frac{{	ext{R}}}{{	ext{Z}}}$$

Answer

Cosine of phase angle difference between current and voltage

Answer

Ratio of useful current to total current $$\frac{{I{	ext{w}}}}{l}$$

Question 6

The 'time constant' of a series RC circuit is

Accepted Answer

$${	ext{RC}}$$

Answer

$$\frac{{	ext{C}}}{{	ext{R}}}$$

Answer

$$\frac{{	ext{R}}}{{	ext{C}}}$$

Answer

$$\frac{1}{{{	ext{RC}}}}$$

Question 7

The power is measured in terms of decibels in case of

Accepted Answer

Electronic equipment

Answer

Transformers

Answer

Current transformers

Answer

Auto transformers

Question 8

Inductance affects the direct current flow

Accepted Answer

At the time of turning on and off

Answer

Only at the time of turning off

Answer

Only at the time of turning on

Answer

At all the time of operation

Question 9

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

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

Answer

The more heat than produced by A.C. when flowing through the same circuit

Answer

The less heat than produced by A.C. flowing through the same circuit

Answer

None of the above