A parallel plate capacitor has a uniform electric field

A parallel plate capacitor has a uniform electric field E in the space between the plates. If the distance between the plates is d and area of each plate is A, the energy stored in the capacitor is :

The energy stored by a capacitor ...(i)

U =	1	CV²...........(i)
	2

V is the p.d. between two plates of the capacitor. The capacitance of the parallel plate capacitor V = E.d.

C =	Aε₀
	d

Substituting the value of C in equation (i)

U =	1	Aε₀	(Ed)² =	1	Aε₀E²d
	2	d		2

1	ε₀E²
2

1	ε₀E²Ad
2