An $AC$ source rated $220\, V, 50\, Hz$ is connected to a resistor. The time taken by the current to change from its maximum value to the $rms$ value is:

An $ac$ current is represented as $i = 5 \sqrt{2} + 10 \cos \left(650 \pi t + \frac{\pi}{6}\right) \text{ A}$. The $r.m.s$ value of the current is:

In an $A.C.$ circuit,the instantaneous current and $E.M.F.$ are represented as $i = i_0 \sin(\omega t - \frac{\pi}{6})$ and $E = E_0 \sin(\omega t + \frac{\pi}{3})$ respectively. The voltage leads the current by

The rms value of the emf given by $E = (8 \sin \omega t + 6 \cos \omega t) \text{ V}$ is:

The output of a step-down transformer is measured to be $24 \ V$,when connected to a $12 \ W$ light bulb. The value of peak current is $...... \ A$. (in $A$)

An alternating current is given by $i = i_1 \sin \omega t + i_2 \cos \omega t$. The rms current is given by