The optical path of monochromatic light is same if it travels `2 cm` thickness of glass or `2.25 cm`, thickness of water. If refractive index of glass is `1.5`, what is the refractive index of water ?

Answer

`1.33`

Explanation

As optical path (in vecuum) `= mu xx` path in medium
`:. mu_(w) xx 2.25 = mu_(g) xx 2.00 = 1.5 xx 2.00`
`mu_(w) = (1.5 xx 2.00)/(2.25) = 1.33`