Question

The dipole moment per unit volume is called__________.

Answer 1

Dielectric Polarization

• A dipole contains both charges positive and negative.
• The alignment of the dipole moments of the permanent or induced dipoles with the direction of the applied electric field is called polarisation.
• There is an excess negative charge in one of the two extremely thin surface layers and an excess equivalent positive charge in the other.
• The induced charges on the surfaces of the dielectric are due to these layers.
• The charges that are induced are not free, but each is bound to a molecule lying on or near the surface.
• These charges are called bound charges or fictitious charges.
• In the remaining dielectric, the net charge per unit volume remains zero.
• Thus, although the dielectric is polarized, as a whole, it remains electrically neutral.

Hence, dipole moment per unit volume is called polarization.