In an a.c. circuit, voltage and current are given by: V = 100 (...

Standard expression of voltage is given by, $V = {V}_{0}sin$\left(\omegat\right)$and for current is given by,$I = {I}_{0}\sin \left(\omegat + ϕ\right)$. Clearly,$ϕ$is the phase difference here. From the given expression,$ϕ = \dfrac{\pi}{3}$.</p><p>Average power dissipated in one cycle is given by,</p><p>${P}_{avg} = {V}_{rms}{I}_{rms}\cos ( ϕ )$</p><p>$= \dfrac{100}{\sqrt{2}} \times \dfrac{100 \times {10}^{- 3}}{\sqrt{2}} \times \cos \left(\dfrac{\pi}{3}\right)$</p><p>$= \dfrac{{10}^{4}}{2} \times {10}^{- 3} \times \dfrac{1}{2}$</p><p>$= \dfrac{10}{4} = 2 . 5W