$A$ parallel plate capacitor has a uniform electric field $\overrightarrow{E}$ in the space between the plates. If the distance between the plates is $d$ and the area of each plate is $A$,the energy stored in the capacitor is: ($\varepsilon_{0} =$ permittivity of free space)

• A
  $\frac{1}{2} \varepsilon_{0} E^{2}$
• B
  $\varepsilon_{0} EAd$
• C
  $\frac{1}{2} \varepsilon_{0} E^{2} Ad$
• D
  $\frac{E^{2} Ad}{\varepsilon_{0}}$