Question

In an ac circuit V and I are given by

V = 150 sin (150 t) V and

I = 150 sin $\left( 150 t + \frac { \pi } { 3 } \right)$ A

The power dissipated in the circuit is

• A. 5625 W
• B. 4825 W
• C. 7450 W
• D. 3425 W

Answer 1

Answer: (A)

5625 W

Answer 2

P = V_rms I_rms cos f

= $\left( \frac { 150 } { \sqrt { 2 } } \right)$ $\left( \frac { 150 } { \sqrt { 2 } } \right)$ cos p/3 = 5625 W