The frequency of $AC$ mains in India is ....... $Hz$.

$A$ group of lamps having a total power rating of $1000 \,W$ is supplied by an $AC$ voltage of $E = 200 \sin(310t + 60^{\circ})$. The $r.m.s.$ value of the current flowing through the circuit is:

Hot wire ammeters are used for measuring

One complete set of negative and positive values of alternating quantities is called

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

The instantaneous values of current and emf in an $AC$ circuit are $I = 1/\sqrt{2} \sin(314t) \, A$ and $E = \sqrt{2} \sin(314t - \pi/6) \, V$ respectively. The phase difference between $E$ and $I$ will be