Question

The refractive index of a medium with permittivity of 2 and permeability of 3 is given by

(a) 3.56

(b) 2.45

(c) 3.21

(d) 1.78

This question was posed to me in class test.

Enquiry is from Snell Law and Critical Angle topic in section EM Wave Propagation of Electromagnetic Theory

Answer 1

The correct choice is (b) 2.45

To explain: The refractive index is given by n = c √(με), where c is the speed of light. Given that relative permittivity and relative permeability are 2 and 3 respectively. Thus n = 3 x 10^8 √(2 x 4π x 10^-7 x 3 x 8.854 x 10^-12) = 2.45.