The polarization in a solid dielectric is related to the electric field \(\overrightarrow E\) and the electric flux \(\overrightarrow D\) according to which one of the following equations?

Concept:

Electric displacement denoted by D is nothing but the charge per unit area that would be displaced across a layer of conductor placed across an electric field. It is also known as electric flux density.

Dielectric is a material that does not have a free charge carrier for conduction. They however contain positive and negative charges which are bound together. 

• They can be easily polarized which means charges inside the material will show a response to an electric field applied externally.
• In Dielectric material, the external field will compel the molecules to align the individual dipole moment along the direction of the applied field.
• They are used to store energy. These materials exist in solid, liquid, and gaseous forms. Some examples of dielectric materials are:
  • Solid Dielectrics – Plastic, Ceramic, Glass, and Mica
  • Dielectric Liquid – Distilled Water.
  • Dielectric Gas – vacuum, nitrogen, Dry Air,  and helium.

Explanation:

Electric displacement is used in the dielectric material to find the response of the materials on the application of an electric field E.

It came from Maxwell's equation, it appears as a vector field quantity.

The SI unit of electric displacement is Cm-2.

Mathematically relation of Electric displacement with the electric field and polarization vector is given by-

 \(D={{\varepsilon }_{0}}E+P\)

or

\(\overrightarrow D = {\varepsilon _0}\overrightarrow E + \overrightarrow P \)

Hence, Option-3 is the correct answer.