A.C Fundamentals, Circuits and Circuit Theory MCQs

Question 1

For a sine wave with peak value Imax the r.m.s. value is

Accepted Answer

0.707

Answer

0.5 Imax

Answer

0.9

Answer

1.414 Imax

Question 2

For a frequency of 200 Hz, the time period will be

Accepted Answer

0.005 s

Answer

0.05 s

Answer

0.0005 s

Answer

0.5 s

Question 3

All the rules and laws of D.C. circuit also apply to A.C. circuit containing

Accepted Answer

Resistance only

Answer

Capacitance only

Answer

Inductance only

Answer

All above

Question 4

The equation of 50 Hz current sine wave having r.m.s. value of 60 A is

Accepted Answer

84.84 sin 3141

Answer

60 sin 25 t

Answer

60 sin 50 t

Answer

42.42 sin 314 t

Question 5

In a pure inductive circuit if the supply frequency is reduced to $$\frac{1}{2},\,$$ the current will

Accepted Answer

Be doubled

Answer

Be reduced by half

Answer

Be four times as high

Answer

Be reduced to one fourth

Question 6

In a pure capacitive circuit if the supply frequency is reduced to $$\frac{1}{2},\,$$ the current will

Accepted Answer

Be reduced by half

Answer

Be doubled

Answer

Be four times at high

Answer

Be reduced to one fourth

Question 7

A sine wave has a frequency of 50 Hz. Its angular frequency is __________ radian/second.

Accepted Answer

100 n

Answer

50 jt

Answer

25 JT

Answer

5 n

Question 8

Skin effect occurs when a conductor carries current at _________ frequencies.

Accepted Answer

High

Answer

Very low

Answer

Low

Answer

Medium

Question 9

In a parallel R-C circuit, the current always _________the applied voltage

Accepted Answer

Leads

Answer

Lags

Answer

Remains in phase with

Answer

None of the above