Question

If the speed of light in water is 2.25 x 10⁸ m/s and the speed in vacuum is 3 x 10⁸ m/s. Calculate the refractive index of water.

Answer 1

Refractive index of water 

= Speed of light in 1 medium (air)/Speed of light in 2 medium (water)

∴  The refractive index of water = 1.33.

Answer 2

π1.v1=π2.v2

Where π=refractive index of medium

v=velocity of light in that medium

By using this formula,

Ans. π=4/3