Question

Assertion
The electric susceptibility of dielectric material is a measure of how easily it polarizes in response to an electric field.
Reason
 The electric susceptibility determines the electric permittivity of the material and thus influences many other phenomena in that medium, from the capacitance of capacitors to the speed of light.
(A)Both assertion and reason are correct and reason is the correct explanation for assertion.
(B) Both assertion and reason are correct but reason is not the correct explanation for assertion.
(C) Assertion is correct but reason is incorrect.
(D) Both assertion and reason are incorrect.

Answer 1

Hint: Electric susceptibility is one of the electric constants which indicate the degree of polarization of a dielectric material placed in an electric field. The electric susceptibility is only related to the polarization of the dielectric material and does not indicate any other phenomena but it may influence phenomena in that medium, from the capacitance of capacitors to the speed of light.

Complete step by step answer:
We must know that Electric susceptibility is a quantitative measure of the displacement of positive and negative charges within a dielectric medium (polarization). It is always a dimensionless positive quantity.
In the CGS system, electric susceptibility is defined as the ratio of polarization (P) to the average electric field (E). i.e.${{\chi }_{e}}=\dfrac{P}{E}$ .
While in the MKS system, it is slightly differed by the inclusion of permittivity of vacuum in the expression, which is given as, ${{\chi }_{e}}=\dfrac{P}{{{\varepsilon }_{0}}E}$.
Now, electric permittivity is a proportionality constant that relates the electric field in a material to the electric displacement in that material. That is, it shows the tendency of the atomic charge in a material to distort in the presence of an electric field.
The Electric permittivity of vacuum is given as, ${{\varepsilon }_{0}}=8.85\times {{10}^{-12}}k{{g}^{-1}}{{m}^{-3}}{{s}^{4}}{{A}^{2}}$ .
In the assertion given that the electric susceptibility of dielectric material is a measure of how easily the dielectric material polarizes and the assertion is true and the electric susceptibility of dielectric material influences many other phenomena because it is a constant. That means a special property of the dielectric medium causes the bent of light in that dielectric or capacitance depends on its nature. But it does not mean that because of the phenomena to influence causes polarization. So, the correct answer is (B).

Note:
The capacitance of the capacitor, speed of light in that dielectric, etc depends on the electric susceptibility but those phenomena do not affect the susceptibility of dielectric because the susceptibility of the dielectric is the absolute property of a particular dielectric.