Question

The expression for refractive index is given by

(a) N = v/c

(b) N = c/v

(c) N = cv

(d) N = 1/cv

I got this question in examination.

This interesting question is from Refractive Index and Numerical Aperture topic in portion EM Wave Propagation of Electromagnetic Theory

Answer 1

The correct option is (b) N = c/v

For explanation: The refractive index is defined as the ratio of the velocity of light in a vacuum to its velocity in a specified medium. It is given by n = c/v. It is constant for a particular material.