Q75 / 120 · NEET 2012 (Mains) · Physics

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

  • A
    $\frac{1}{2} \varepsilon_0 E^2$
  • B
    $E^2 A d / \varepsilon_0$
  • Correct answer
    C
    $\frac{1}{2} \varepsilon_0 E^2 A d$
  • D
    $\varepsilon_0 E A d$

Solution

Energy density for a parallel plate capacitor $=\frac{1}{2} \varepsilon_0 E^2$ and volume $=A d$ Total energy $=$ energy density $\times$ volume $$ \begin{aligned} & =\left(\frac{1}{2} \varepsilon_0 E^2\right) \times(A d) \\ & =\frac{1}{2} \varepsilon_0 E^2 A d \end{aligned} $$

Hence, the correct answer is option: 'C'.

Relevant Questions