The refractive index of diamond is 2.47 and that of glass is 1.51. How much faster does light travel in glass than in diamond?

​​​Solution:- Given The refractive index of diamond, μ = 2.47  ----------------------(1)

that of glass, μ' = 1.51  -----------------------(2)

As refractive index = c/v

c be the velocity of light in vacuum while v is the velocity of light in that medium

Taking the ratio:

μ/μ' = v'/v = 2.47/1.51 = 1.636

=>  v' = 1.636 times v

ie velocity in glass medium = 1.636 times the velocity of the light in diamond