The electric force acting between two point charges kept at a certain distance in vacuum is $16 \ N$. If the same two charges are kept at the same distance in a medium of dielectric constant $8$,the electric force acting between them is . . . . . . .

In a medium of dielectric constant $K$,the electric field is $\vec E$. If $\varepsilon_0$ is the permittivity of free space,the electric displacement vector is:

What is the dimensional formula for the intensity of polarization?

$Assertion \; (A)$: Non-polar materials do not have any permanent dipole moment.
$Reason \; (R)$: When a non-polar material is placed in an electric field,the centre of the positive charge distribution of its individual atom or molecule coincides with the centre of the negative charge distribution.
In the light of the above statements,choose the most appropriate answer from the options given below:

Explain the polarization of a nonpolar molecule in a uniform electric field and define linear isotropic dielectrics.

Choose the correct relation between polarisation $P$ and electric susceptibility $\chi_{e}$ of a dielectric material. ($E =$ electric field)