Power in AC Circuits, Wattless Current NEET Questions

Physics - Electromagnetic Induction and Alternating Currents

Power in AC Circuits, Wattless Current MCQ Questions


1.
In an AC circuit, the voltage and current are given by V = V₀ sin(ωt) and I = I₀ sin(ωt + π/2), respectively. The average power dissipated in the circuit over a complete cycle is:
A.
V₀I₀/2
B.
V₀I₀/4
C.
Zero
D.
V₀I₀
😑 View Answer Rough Work Error
ANSWER :
C. Zero
2.
The power factor of a circuit containing only a pure inductor or a pure capacitor is:
A.
1
B.
0.5
C.
0
D.
-1
😑 View Answer Rough Work Error
ANSWER :
C. 0
3.
In a series LCR circuit with resistance R = 10Ω, inductive reactance XL = 30Ω, and capacitive reactance XC = 20Ω, connected to an AC source of 220 V rms, the power dissipated in the circuit is:
A.
484 W
B.
968 W
C.
1100 W
D.
2200 W
😑 View Answer Rough Work Error
ANSWER :
A. 484 W
4.
Which of the following statements is true regarding wattless current?
A.
It occurs in circuits with zero resistance.
B.
It results in maximum power dissipation.
C.
It is present in purely resistive circuits.
D.
It is absent in purely reactive circuits.
😑 View Answer Rough Work Error
ANSWER :
A. It occurs in circuits with zero resistance.
5.
The average power supplied to a purely capacitive AC circuit over one complete cycle is:
A.
Vrms × Irms
B.
1/2 × Vrms × Irms
C.
Zero
D.
Vrms × Irms × cos(ϕ)
😑 View Answer Rough Work Error
ANSWER :
C. Zero
6.
In an AC circuit with voltage V = V₀ sin(ωt) and current I = I₀ sin(ωt - π/3), the power factor of the circuit is:
A.
1/2
B.
√3/2
C.
√2/2
D.
1/√2
😑 View Answer Rough Work Error
ANSWER :
A. 1/2