Question

Light travels through air at 300 million ms⁻¹. On entering water it slows down to 225 million ms⁻¹. Calculate the refractive index of water.

Answer 1

Here, mediums 1 and 2 are air and water, respectively.

Refractive index of water = `"Speed of light in air"/"Speed of light in water"`

= `(300  "million ms"^-1)/(225  "million ms"^-1)` 

=  1.33

Therefore, the refractive index of water is 1.33.