A capacitor of capacitance ' C ' is connected across a.c. source of voltage V as $\mathrm{V}=\mathrm{V}_0 \sin \omega \mathrm{t}$. The displacement current between the plates of the capacitor would be

A resistor of $400 \Omega$, an inductance of 0.4 H are in series with an a.c. source of e.m.f. $\mathrm{E}=200 \sqrt{2} \sin (1000 \mathrm{t})$. The power factor of the circuit is

In the series LCR circuit shown in figure, the impedance is

An alternating current is given by $\mathrm{I}=100 \sin (50 \pi t)$. How many times will the current become zero in one second?