Polarisation is defined as the ____________.

The correct answer is option 3):(Dipole moment per unit volume)

Concept:

• The positive and negative charges are separated by a small distance and constitute dipole
• Polarizability is the tendency of an atom's electron cloud to be distorted from its normal shape by the application of an external electric field.
• The dipole will align with the direction of the applied electric field and it is called polarization. It is expressed in units of coulombs per metre square
• Polarisation is defined as the Dipole moment per unit volume
• When the molecules of a dielectric are placed in the electric field, their negatively charged electrons separate slightly from their positively charged cores. This separation is referred to as polarization.
• The molecules acquire an electric dipole moment.
• The electric dipole moment p of two charges +q and −q separated by a distance l is a vector of magnitude p = ql with a direction from the negative to the positive charge.
• When we placed the Dielectric in an external field E, the positive and negative charges are displaced from their equilibrium position as shown in the above diagram

Additional InformationProperties of Dielectric material:

• The band energy gap in the dielectric materials is very large.
• The coefficient of temperature for resistance is negative.
• They have high resistivity.
• They have a strong attraction between electrons and the parent nucleus.
• They have a very low electrical conductivity of these materials.
• That's why they are basically electrical insulators.
• The electric field outside the dielectric gets modified due to the induced dipoles
• The induced dipole aligns in the direction of the applied electric field. Due to polarization, dielectrics can store energy