Question

A beaker is filled with water to a height of 12.5 cm. The apparent depth of a needle at the bottom of the beaker is 9.4 cm. Find the refractive index of water.

Answer 1

Actual depth of the needle in water, h₁ = 12.5 cm

Apparent depth of the needle in water, h₂ = 9.4 cm

Refractive index of water = μ

The value of μ can be obtained as follows:

μ = `h_1/h_2`

= `12.5/9.4`

= 1.329

≈ 1.33

Hence, the refractive index of water is about 1.33.