In an a.c. circuit, voltage and current are given by: V = 100 sin ( 100 t ) V and I = 100 sin 100 t + π 3 mA respectively. The average power dissipated in one cycle is :

Step-by-step solution

Standard expression of voltage is given by, V = V 0 sin ω t and for current is given by, I = I 0 sin ω t + ϕ . Clearly, ϕ is the phase difference here. From the given expression, ϕ = π 3 . Average power dissipated in one cycle is given by, P a v g = V r m s I r m s cos ( ϕ ) = 100 2 × 100 × 10 - 3 2 × cos π 3 = 10 4 2 × 10 - 3 × 1 2 = 10 4 = 2 . 5 W