Dielectrics are non-conducting substances. In contrast to conductors, they have no (or a negligible number of ) charge carriers.
Example of the dielectric materials are: Mica, glass, plastics, and the oxides of various metals.
The dipole moment per unit volume is called polarisation and is denoted by P. For linear isotropic dielectrics,
PE = χ
where χe is a constant characteristic of the dielectric and is known as the electric susceptibility of the dielectric medium.