MCQs of Alternating Current

Showing 161 to 168 out of 168 Questions

161.

A current of

\frac{25}{π} H_{Z}

frequency is passing through an A.C. circuit having series combination of R = 100

Ω

and L = 2 H, the phase difference between voltage and current is _____ .

162.

In A.C. circuit having only capacitor, the current _____ .

(a)	lags behind the voltage by $\frac{π}{2}$ in phase
(b)	leads the voltage by $π$ in phase
(c)	leads the voltage by $\frac{π}{2}$ in phase
(d)	lags behind the voltage by $π$ in phase

163.

An alternating voltage given as

V = 100 \sqrt{2}

sin 100t volt is applied to a capacitor of 1

μ F

. The current reading of the ammeter will be equal to _____ mA.

164.

For a step-down transformer which of the following is correct ?

(a)	Output voltage > Input voltage
(b)	Output voltage < Input voltage
(c)	Number of turns in primary coil = number of turns in the secondary coil
(d)	None of these

165.

For L-C-R A.C. circuit resonance frequency is 5000 Hz and frequencies at half power points are 4950 Hz an 5050 Hz. The Q- factor is _____.

166.

For an A.C. L-C-R series circuit at resonant frequency, which of the following is wrong ?

(a)	Magnitude of reactance due to L and C are equal.
(b)	Phase change due to L is equal and opposite to phase change due to C.
(c)	Value of resistance is zero.
(d)	Impedance has only real component.

167.

If angular frequency of an A.C. source used in L-C-R circuit is decreased, then inductive reactance _____ and capacitive reactance _____ .

168.

Current of

\frac{50}{π}

Hz frequency is passing through an A.c. circuit having series combination of resistance R = 100

Ω

and inductor

L = \sqrt{3} H

. The phase difference between the voltage and current is _____ .

Showing 161 to 168 out of 168 Questions