MCQs of Alternating Current

Alternating Current MCQs

MCQs of Alternating Current

Showing 41 to 50 out of 168 Questions

41.

The force constant of a spring corresponds to _____ in electrical circuit.

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

42.

In an A.C. circuit the inductive reactance is defined as _____

(a)	Z_L = -jωL
(b)	$Z_{L} = - \frac{j}{ωL}$
(c)	$Z_{L} = - \frac{ωL}{j}$
(d)	Z_L = ωL

43.

In an A.C. circuit, the capacitive reactance is defined as _____

(a)	Z_C = jωC
(b)	$Z_{C} = - \frac{1}{j ω C}$
(c)	$Z_{C} = \frac{j}{ω C}$
(d)	$Z_{C} = \frac{1}{j ω C}$

44.

Capacitance reactance of a capacitor for a D.C. circuit is _____

(a)	zero
(b)	ωC
(c)	$\frac{1}{ω C}$
(d)	infinite

45.

The expression for the A.C. supply voltage of 234V and frequency of 50 Hz in our house is _____

(a)	V = 165 sin (100 Πt)
(b)	V = 331 sin (100 Πt)
(c)	V = 234 sin (100 Πt)
(d)	V = 331 cos (100 Πt)

46.

The time taken by A.C. voltage of frequency 50 Hz to change from zero to maximum is _____ ms.

(a)	5
(b)	10
(c)	20
(d)	50

47.

A coil of self inductance of 1H and resistance 200 Ω is connected to an A.C source of frequency

\frac{200}{π}

Hz. The phase difference between voltage and current will be _____

(a)	30°
(b)	63°
(c)	45°
(d)	75°

48.

The maximum value of an A.C. voltage coming in our houses is _____ % more than that of its r.m.s value.

(a)	1.414
(b)	4.14
(c)	14.14
(d)	41.4

49.

For series L -C -R circuit, L = 10 mH and C = 10^-7 F. If resonance frequency is made double without changing inductor, the capacitance must be _____ μF.

(a)	0.25
(b)	0.025
(c)	2.5
(d)	25

50.

For an L - C - R series, the Q-factor is _____

(a)	$Q = R \sqrt{\frac{L}{C}}$
(b)	$Q = \frac{1}{R} \sqrt{\frac{L}{C}}$
(c)	$Q = \frac{1}{R} \sqrt{\frac{C}{L}}$
(d)	$Q = \frac{1}{C} \sqrt{\frac{R}{L}}$

Showing 41 to 50 out of 168 Questions