Each plate of a parallel‑plate capacitor is a square of side 0.0479 m, and the plates are separated by 0.479 × 10 − 3 m. The capacitor is charged and stores 8.11 × 10 − 9 J of energy. Find the electric field strength E inside the capacitor.

Explanation:

It is known that the relation between electric field and potential is as follows.

             E =

And, formula to calculate the capacitance is as follows.

           C =

              =

              = F

Hence, energy stored in a capacitor is as follows.

         W =

          V =

        E =

            =

            =

Thus, we can conclude that electric field strength E inside the capacitor is .