Q. The instantaneous values of alternating current and voltage in a circuit are given as i = (1/√2) sin(100πt) ampere e = (1/√2) sin(100πt + π/3) volt The average power in watts consumed in the circuit is
A) 1/4
B) √3/4
C) 1/2
D) 1/8
Explanation
[Solution from source] Peak values are 1/√2, so Irms = Vrms = 1/2. The phase difference is π/3, so P = Vrms·Irms·cos φ = ½ × ½ × ½ = 1/8 W. Using peak values instead of rms values gives a larger, wrong answer. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.