Prove that an ideal inductor does not dissipate power in an a .c circuit.
Let us consider the e.m.f. of the AC signal of the form
Since in the inductor current lags behind e.m.f. therefore current I at an instant is given by
Thus power through an inductor at an instant of time
Now average power in a complete cycle
Thus average power dissipated in an ideal inductor is zero over a full AC cycle