If an $AC$ main supply is given to be $220\,V$,the average $emf$ during a positive half cycle will be.....$V$.

The $r.m.s.$ voltage of the waveform shown is:

An alternating current at any instant is given by $i = [6 + \sqrt{56} \sin (100 \pi t + \frac{\pi}{3})] \ A$. The rms value of the current is . . . . . . . (in $A$)

An $AC$ source has a voltage of $220V$ and a frequency of $50\,Hz$. How much time (in $sec$) does it take for the voltage to reach zero from its maximum value?

Match the following:

Currents	$r.m.s.$ values
$(A) \ x_0 \sin \omega t$	$(i) \ x_0$
$(B) \ x_0 \sin \omega t \cos \omega t$	$(ii) \ \frac{x_0}{\sqrt{2}}$
$(C) \ x_0 \sin \omega t + x_0 \cos \omega t$	$(iii) \ \frac{x_0}{2\sqrt{2}}$

In an a.c. circuit $I=100 \sin 200 \pi t$. The time required for the current to achieve its peak value will be