Question

Explain, in detail, why the dielectric constant does not depend on the thickness of the material.

**Hint** Recall that dielectrics are made of electrical insulators. What happens when an insulator is placed into an electric field? What happens at the edge of an insulator? What happens inside the insulator?

Answer 1

The dielectric constant of a material depends on the physical properties of the material and not on the geometrical properties. The electric field induced inside the material will reduce the total electric field because the induced field is opposite in the direction of the applied electric field.

When the material is placed inside the electric field then the edge of the insulator will acquire an induced charge whose surface charge density can be given as

where polarisation vector while is the direction of normal perpendicular to the surface.Inside the insulator, an electric field is induced and there is a corresponding dipole moment.