Question 682: Electrostats & Capacitance

Question

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

Accepted Answer

Capacitance of a parallel plate capacitor is
$$C = {{{\varepsilon _0}A} \over d}$$   ...(i)
Potential difference between the plates is
V = Ed    ...(ii)
The energy stored in the capacitor is
$$U = {1 \over 2}C{V^2} = {1 \over 2}\left( {{{{\varepsilon _0}A} \over d}} \right){\left( {Ed} \right)^2}$$   (Using (i) and (ii))
$$ = {1 \over 2}{\varepsilon _0}{E^2}Ad$$

Answer

$${1 \over 2}{\varepsilon _0}{E^2}$$

Answer

$${{{E^2}Ad} \over {{\varepsilon _0}}}$$

Answer

$${1 \over 2}{\varepsilon _0}{E^2}Ad$$

Answer

$${\varepsilon _0}EAd$$

Electrostats & Capacitance

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

Choose the correct answer: