Answer: 

Orientational Polarization:- 

• Orientational polarization is found in polar dielectrics that possess permanent dipole moments. In the absence of an electric field, the permanent molecular dipoles are distributed randomly in all directions so that their net dipole moment is zero.
• In the presence an external electric field, individual dipoles experience a torque, which will tend to align them along the direction of the applied electric field, E. According to the strength of the field, the number of dipoles oriented along the direction of field will vary. For a very strong electric field all molecular dipoles may completely aligned along the direction of the field.

• If N is the number of molecules per cubic meter, then the orientational polarization$\mathrm{\overrightarrow{P_o}}$ will be

$\mathrm{\overrightarrow{P_o}=N \space \alpha_o \overrightarrow{E}}$

• The orientational polarization is temperature and frequency dependent. It takes relatively longer time to align completely along the applied field. According to Langevin and Debye, the orientational polarizabilityao at an absolute temperature T is,

$\mathrm{\alpha_o=\dfrac{p_o^2}{3k_BT}}$

where $\mathrm{p_o}$ is the induced dipole moment due to the orientational polarization and kg is the Boltzmann's constant. 

Thus, the orientational Polarization $P_o$ is given as

$\mathrm{P_o=N \alpha_oE=\dfrac{N p_o^2E}{3k_BT}}$