Question

A ray of light is incident on a medium with angle of incidence 'i' and is refracted into a second medium with angle of refraction 'r'. The graph of sin i versus sin r is as shown. Find the ration of the velocity of light in the first medium to the velocity of light in the second medium

Answer 1

Refractive Index may be defined as the Ratio of sine of angle of Incidence to the sine of angle of Refraction.

It may also be defined as the Ratio of the speed of light in that medium with respect to other medium.

Now, Speed of the light in that medium  can be told with the help of the Refractive Index.

      Refractive Index = Sini/Sinr

where i is the angle of Incidence and r is the angle of the Refraction.

But, Refractive Index = Speed of light in medium 1/Speed of light in medium 2.

∴ Speed of light in medium 1/Speed of light in medium 2.  = Sini/Sinr

By Substituting the Numerical Values, We can find the Ratio easily.

Hope it helps.