Answer to Question #103169 in Electricity and Magnetism for Ajay

Question

State, giving reasons, whether the following statements are True or False:
(1) When a dielectric material is inserted between the parallel plates of a capacitor, the
electrostatic energy stored between the plates increases.

Answer 1

If a plate having the plate area A of the parallel plate capacitor,

d is the distance between the plates.

So, Capacitance

$C_o=\dfrac{\epsilon_o A}{d}$

when the dielectric material is inserted between the plates.

Let the di electric constant of the material =K

$C=\dfrac{K\epsilon_o A}{d}$

$C=KC_o$

We know that the energy stored in the capacitor is

$E=\dfrac{K\epsilon AV^2}{2d}$

$E\propto kC_o$

So, it can store more charges and maintain much potential difference.

Hence energy of the plates will increase.