Energy per unit volume for a capacitor having area A and separation d kept at potential difference V is given by :-

Question

( A ) $\frac{1}{2} CV^2$
( B ) $\frac{1}{2} \varepsilon_0 \frac{V^2}{d^2}$
( C ) $\frac{1}{2 \varepsilon_0} \frac{V^2}{d^2}$
( D ) $\frac{Q^2}{2C}$