CBSE Class 10 Answered

Pls post each question seperately.

Given, refractive index of water w.r.t. air = 4/3

and,  refractive index of glass  w.r.t. air = 3/2

Let, 'c' be the speed of light

Then, speed of light in water = c / refractive index of water w.r.t. air  .........................[1]

and, speed of light in glass = c /  refractive index of glass  w.r.t. air .........................[2]

So, refractive index of water w.r.t glass = speed of light in glass / speed of light in water

                                                                      = (4/3) / ( 3/2)

                                                                      = 8/9.

Fron eqns [1] and [2], it is clear that, light travels faster in water.