What is the dimensional formula for the intensity of polarization?

What is a dielectric?

$Assertion \; (A)$: 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:

The dielectric constant of a metal is ........ .

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 . . . . . . .

On what does the extent of polarization depend?