Question

Choose the correct option representing the energy density between the plates of a parallel plate capacitor with plate area A, plate separation d and potential difference V.

(1) \(\frac{\varepsilon _0 V^2}{2d^2}\)

(2) \(\frac{\varepsilon _0Vd^2}{2}\)

(3) \(\frac{\varepsilon _0 AV^2}{2d}\)

(4) \(\frac{\varepsilon _0 AV^2}{2d^2}\)

Answer 1

Correct option is : (1) \(\frac{\varepsilon _0 V^2}{2d^2}\) 

\(E = \frac{V}{d}\)

Energy density = \(\frac{1}{2}\varepsilon _0E^2\)

\( = \frac{1}{2}\frac{\varepsilon _0 V^2}{d^2}\)