Energy Density of a Parallel Plate Capacitor:
If the area of cross section of each plate of a parallel plate capacitor is A, and the charged Q is given to the plates. Then, the electric field between its plates,
Though equation \(\left(U=\frac{1}{2} \frac{Q^{2}}{C}\right)\) is obtained for a parallel plate capacitor but it is also true for conservative electric field. Thus, for places, where there is electric field, electric potential energy per unit volume will be \(\frac{1}{2}\)ε0E2 . For parallel plate capacitor, E will be uniform and hence, U will be uniform.
