$A$ $280 \ \Omega$ electric bulb is connected to a $200 \ V$ electric line. The peak value of current in the bulb will be:

Two sinusoidal voltages of the same frequency are shown in the diagram. What is the frequency, and the phase relationship between the voltages? (Frequency in $Hz$, Phase lead of $N$ over $M$ in radians)

In a certain circuit,the current changes with time according to $i = 2\sqrt{t}$. The r.m.s. value of the current between $t = 2 \ s$ and $t = 4 \ s$ will be:

The instantaneous value of an alternating current is given by $I = 50 \sin(100 \pi t)$. It will achieve a value of $25 \ A$ after a time interval of (given $\sin 30^{\circ} = 0.5$):

The variation of $EMF$ with time for four types of generators is shown in the figures. Which amongst them can be called $AC$?

An $ac$ source is rated at $220V, 50 Hz$. The time taken for voltage to change from its peak value to zero is.....$sec$.