Which of the following effects is predominant when a dielectric material is polarised?

When dielectric materials are polarized, charged particles or polar molecules can move freely, which causes current to flow in the material. This is because the charged particles or molecules reorient themselves to align with the electric field.

Concept:

• Polarization: Electronic materials have permanent electric dipole moments; the vector field expression of concentration of stable electric dipole moments is called the electric potential polarization.
• Polarization occurs when an electric field twists the negative cloud of electrons around the positive atomic nuclei in a direction reverses the field.

P = q d

\(\text{P}=\frac{\text{q }\!\!~\!\!\text{ d}}{\text{V}}=\frac{\text{q}}{\text{A}}\frac{\text{d}}{\text{d}}=\frac{\text{q}}{\text{A}}\)

• The SI unit of polarization is C / m². Generally, the area is very small so it can be taken as C / cm².

P = α E

Where α is a constant called the polarizability.

• The polarizability is determined experimentally and it depends on the properties of the atom.

Where P is polarization, q is a charge, V is volume, d is a dimension of material, and A is area.

• A dielectric material gets polarized when it is placed in an electric field.
• The field produces due to the polarization of material to minimize the effect of the external field. Hence, the electric field inside a dielectric decrease when it is placed in an external electric field.

P = α E

Where α is a constant called the polarizability.

So polarization is the linear function of the applied electric field.