Question

A coin at the bottom of a trough containing water to a depth of 15 cm appears to be 3.75 cm raised above from the bottom. Calculate the refractive index of water.

Answer 1

Given:

Real depth of the trough (h) = 15 cm

Apparent shift (S) = 3.75 cm

Formula:

Apparent depth (h') = Real depth (h) − Apparent shift (S)

= 15 − 3.75

= 11.25 cm

Refractive index (μ) = `"Real depth (h)"/"Apparent depth (h')"`

= `15/11.25`

= `1500/1125`

= `4/3`

= 1.33

The refractive index of water is 1.33.