Alternating Current  MCQs

MCQs of Alternating Current

Showing 31 to 40 out of 168 Questions
1 2 3 4 5 6
31.
The output power in a step-up transformer is _____
(a) greater than the input power
(b) equal to the input power
(c) maintained even during the power cut
(d) less then the input power
Answer:

Option (d)

32.
In an A.C. circuit current is 2A and voltage is 220 V and power is 40 W, power factor is _____
(a) 0.9
(b) 0.09
(c) 1.8
(d) 0.18
Answer:

Option (b)

33.
If complex number represented by Z =Z ejθ then ejθ = _____
(a) cosθ
(b) j sin θ
(c) cosθ - sinθ
(d) cosθ + j sinθ
Answer:

Option (d)

34.
The force constant corresponds to _____ in electric quantity.
(a) resistance
(b) inductance
(c) capacitance
(d) inverse of capacitance
Answer:

Option (d)

35.
The displacement in Newton law corresponds to _____ is electrical quantity,
(a) electromagnetic force
(b) current
(c) electric charge
(d) the rate of change of electric charge
Answer:

Option (c)

36.
A coil having inductance of 1 mH is connected to an A.C. source, its inductive reactance will obtained to 1Ω then what will be the angular frequency ( in rad/s) of an A.C. source ?
(a) 103
(b) 10
(c) 10-3
(d) 1
Answer:

Option (a)

37.
The reactance of a capacitor of 1π in an A.C. circuit having frequency of 50Hz is _____
(a) 100Ω
(b) 10Ω
(c) 50Ω
(d) 10-2Ω
Answer:

Option (d)

38.
An LCR series circuit with L = 0.5H, C= 10 × 10-6 F, R = 100Ω is connected to an A.C. source of frequency of 50 Hz. The impedance of the circuit is _____
(a) 1.8765 Ω
(b) 18.76 Ω
(c) 189.6 Ω
(d) 101.3 Ω
Answer:

Option (c)

39.
Capacitive reactance of a capacitor is _____
(a) XL
(b) ZL
(c) XC
(d) ZC
Answer:

Option (d)

40.
Which of the following gives a correct correspondence between electrical and mechanical quantities ?
(a) current → velocity
(b) current → acceleration
(c) current → displacement
(d) none of these
Answer:

Option (a)

Showing 31 to 40 out of 168 Questions
1 2 3 4 5 6