Question

In an a.c. circuit, the instantaneous values of e.m.f. and current are $E=200sin314t\left(volt\right)andI=sin(314t+\frac{\pi }{3})A$. The average power consumed in watts is

• A. 100
• B. 200
• C. 50
• D. 25

Answer 1

The correct option is C

50

$P_{av}=E_{rms}{I}_{rms}cos\varphi$

$=\frac{200\times 1}{2}\times cos\frac{\pi }{3}$

$=\frac{200\times \frac{1}{2}}{2}=50$