MCQs of Alternating Current

Alternating Current MCQs

MCQs of Alternating Current

Showing 131 to 140 out of 168 Questions

131.

The band-width of a series resonant circuit is 500 Hz and the resonant frequency is 5000 Hz. The value of R is 100

Ω

, then the inductance of the coil will be _____

(a)	$\frac{1}{π} H$
(b)	$\frac{1}{2 π} H$
(c)	$\frac{1}{5 π} H$
(d)	$\frac{1}{10 π} H$

132.

In an oscillating system, a restoring force is provided by a/an _____

(a)	capacitor
(b)	inductance
(c)	resistance
(d)	Both (A) and (B)

133.

The equivalent inductance of two inductors is 2.1 H, when connected in parallel and 10 H when connected in series, then the individual inductances are _____

(a)	8 H, 2 H
(b)	5 H, 5 H
(c)	7 H, 3 H
(d)	6 H, 4 H

134.

On increasing the angular frequency of an A.C. source used in a L - C - R series circuit, the capacitive reactance _____ and inductive reactance _____

(a)	decreases, decreases
(b)	increases, increases
(c)	decreases, increases
(d)	increases, decreases

135.

If in an A.C. L - C series circuit, if

X_{L} < X_{C}

, then current _____

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

136.

An alternating voltage given as

V = 200 \sqrt{2}

sin 100 t V is applied to a capacitor of

2 μ F

. The current reading of the ammeter will be equal to _____mA

(a)	100
(b)	40
(c)	80
(d)	20

137.

In an A.C. circuit, current is 2 A and voltage is 220 V. If consumed power is 80 W, then power factor will be _____

(a)	0.9
(b)	0.18
(c)	1.8
(d)	0.09

138.

In an A.C. L-R series circuit,

X_{L} = 3 R

. Now, a capacitor with

X_{C} = R

is added in series. The ratio of new to old power factor is _____

(a)	1
(b)	2
(c)	$\frac{1}{\sqrt{2}}$
(d)	$\sqrt{2}$

139.

The effective r.m.s. value of an A.C. current in a circuit is 10 A. The peak value of current is _____

(a)	10 A
(b)	5 A
(c)	14.14 A
(d)	0.707 A

140.

The dimensions of R - C are same as the dimensions of which of the followings ?

(a)	LR
(b)	$\frac{L}{R}$
(c)	RLC
(d)	$\frac{R}{L}$

Showing 131 to 140 out of 168 Questions