Question

What are polar non-polar dielectric, give one example of each? Define dielectric constant.

Answer 1

Hint: The term polar refers that there is an inherent charge separation present in the medium when there is no external electric field. The term non-polar signifies there is no charge separation in the absence of an electric field. Materials which show the property of polarity are called polar materials and materials which do not have this property are called non-polar. A dielectric is an insulator which does not allow charge to flow through it.

Complete step by step answer:
Dielectrics: Dielectrics are electrical insulators that get polarized in the presence of an electric field. Since it is an insulator it does not allow charge to follow through but will produce charge separation, so positive is shifted towards the direction of the electric field, while the negative charges will align themselves opposite to the direction of the electric field. This creates an internal electric field inside the dielectric which opposes the external electric field.

Polar Dielectrics: Polar dielectrics are materials which have an inherent dipole moment. So the positive and negative charges are separated by a small distance in the absence of an electric field. If an external electric field is applied, the dipoles reorient themselves along the direction of the field. Ammonia and water is a good example of polar dielectrics.

Non-Polar Dielectrics: Non-Polar dielectrics are materials which do not have an inherent dipole moment. So the positive and negative charges are not separated by a small distance in the absence of an electric field. Usually the positive and negative are close to each other and the distance between them is approximately zero. So when an electric field is applied the charges are separated and the positive charges will be concentrated on the left side and negative charges on the right side when an electric field is applied from right to left. Benzene and methane are good examples of non-polar dielectrics.

Note: Dielectrics are used for energy storage since they can store electrical energy inside them.
Capacitors can be made from dielectrics.
Dielectrics are an important concept to explain various phenomena in physics mainly in the field of electronics, optics, solid-state physics etc..