Electromotive force — UPSC Physics Optional CSE 1989 Paper I

An electromotive force p_0 \sin pt + E_1 \sin 2 pt is impressed on a circuit containing an inductor and a resistor. Set up the differential equation obeyed by the current and show that in the steady state the current comprises two sinusoidal terms. Calculate the average power dissipation in the circuit. What is the difference, if any, between a varying current and an alternating current?