A parallel plate condenser has a uniform electric field E(V/m) in the space between the plates. If the distance between the plates is d(m) and area of each plate is A(m²) the energy (joules) stored in the condenser is

Options

(a) E² Ad / ?￢ﾂﾀ
(b) 1/2 ?￢ﾂﾀ E²
(c) ?￢ﾂﾀ E Ad
(d) 1/2 ?￢ﾂﾀ E² Ad

Correct Answer:

1/2 ?￢ﾂﾀ E² Ad

Explanation:

U = 1/2 CV²
U = 1/2 (A ?￢ﾂﾀ / d) (Ed)²
= 1/2 ?￢ﾂﾀ E² Ad