Question

Alternating voltage and current in circuit is given as

V = (100 sinωt) volt

\(I =100sin\left(\omega t + \frac {\pi}{3}\right)mA\)

Find average power dissipated in circuit. 

(1) 2.5 w 

(2) 5 w 

(3) 10 w 

(4) 20 w

Answer 1

Correct option is (1) 2.5 w 

P_avg = IV cos\(\phi\) = \(\frac {100}{\sqrt {2}} \times \frac {100\times 10 ^{-3}}{\sqrt {2}}cos 60 ^\circ = 2.5 \,w\)