$A$ $10\, \Omega$ resistance is connected across $220\, V - 50\, Hz$ $AC$ supply. The time taken by the current to change from its maximum value to the rms value is $....\, ms$.

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?

In an $ac$ circuit,the instantaneous voltage $e(t)$ and current $i(t)$ are given by $e(t) = 5[\cos \omega t + \sqrt{3} \sin \omega t] \ V$ and $i(t) = 5[\sin(\omega t + \frac{\pi}{4})] \ A$. Determine the phase relationship between voltage and current.

If the emf of an $AC$ source is given by $E = 6 \sin \omega t + 4 \sin 2 \omega t \text{ V}$,then the rms value of the emf is

In an $AC$ circuit,the peak value of voltage is $423 \ V$. Its effective voltage is .......... $V$.

Match the following current $\text{r.m.s.}$ values:

$(A) \ x_0 \sin \omega t$	$(i) \ x_0$
$(B) \ x_0 \sin \omega t \cos \omega t$	$(ii) \ \frac{x_0}{\sqrt{2}}$
$(C) \ x_0 \sin \omega t + x_0 \cos \omega t$	$(iii) \ \frac{x_0}{2 \sqrt{2}}$