Question

what do you mean by refractive index of a transparent medium? Light enters from air to glass plate having refractive index 1.50. What is the speed of light? Speed of light in air 3 x 108 m/s.

Answer 1

Refractive index is the ratio of the speed of light in air or vacuum to that of the speed of light in a given medium.

Here refractive index = speed of light in air / speed of light in glass

As refractive index = 1.5

therefore, 1.5=speed of light in air i.e 3*10 8/speed of light in glass

i.e speed of light in glass=3*10 8/1.5 (here 8 is power of 10or 10 raise to power 8)

=2*10 8.