An a.c. source of e.m.f. `epsilon = epsilon_0 sin omegat` is connected in series with a pure resistance R only. Derive an expression for the instantaneous power of this circuit and show that it is pulsating in nature.

An a.c. source given b V = V_0 sin omegat is connected to a pure indutance L in a circuit. If I_0 is the peak value of the a.c., then the instantaneous power in the inductor is

An Ac e.m.f. epsilon = epsilon_0 sin omegat is applied to a circuit containing resistance R, inductance L and capacitance C in series. Write the expression for current in the circuit. Obtain the condition of resonance. In a series L-C-R circuit, R = 60Omega L = 40 mH and C = 400 muF . Determine the resonant frequency.

An a.c. is given by I = I_0 sin omegat . Derive the expression for tis r.m.s value.