In an a. c. circuit, the instantaneous e.m.f.

In an a. c. circuit, the instantaneous e.m.f. and current are given by e $=100 \sin 30 \mathrm{t} \mathrm{i}=20 \sin \left(30 \mathrm{t}-\frac{\pi}{4}\right)$ In one cycle of a.c., the average power consumed by the circuit and the wattless current are, respectively.