Question

Question 5
The refractive index of diamond is 2.42. What is the meaning of this statement?

Answer 1

The refractive index is defined as the ratio of the velocity of light in vacuum to its velocity in a specified medium. The refractive index of diamond is 2.42 means that it is 2.42 times optically denser medium than vaccum. Therefore the speed of light will be less in this medium, i.e. 1.23 $\times$ ${10}^8$ m$s^{-1}$ (= 3 $\times$ ${10}^8$ m$s^{-1}$/2.42) as compared to the speed of light in vacuum.