Question

A parallel plate capacitor has a uniform electric field `overset(->)("E")` in the space between the plates. If the distance between plates is 'd' and the area of each plate is 'A', the energy stored in the capacitor is ______ 

(ε₀ = permittivity of free space)

Options

• `1/2 (epsilon_0 EA)/d`

• `1/2 (epsilon_0 Ad)/E^2`

• `1/2 (epsilon_0E^2A)/d`

• `1/2 epsilon_0 E^2Ad`

Answer 1

A parallel plate capacitor has a uniform electric field 'E' in the space between the plates. If the distance between plates is 'd' and the area of each plate is 'A', the energy stored in the capacitor is `underline(1/2 epsilon_0 E^2Ad)`.

Explanation:

`C = (epsilon_0A)/D`

 Energy stored = `1/2 CV^2`

= `1/2 ((Aepsilon_0)/d)(E . d)^2 =1/2 (Aepsilon_0)/d xx E^2d^2 = 1/2epsilon_0E^2Ad`