When a.c. source is connected across a pure capacitor, the correct phase relation between current and emf is shown in figure.

In series LCR circuit $R = 10\,\Omega$ and impedance is $30\,\Omega$. An r.m.s. voltage $210$ V, is applied across the circuit. The true power consumed in AC circuit is

For a series LCR circuit inductive reactance $X_L$ is equal to resistance $R$ and also equal to twice the capacitive reactance $X_C$. The impedance of the circuit and the phase difference between voltage V and current i are respectively

An alternating voltage $e = 150\sqrt{2}\sin 100t$ volt is applied to a capacitor of capacity $2\ \mu\text{F}$. The root mean square value of current in the circuit is