Question

The refractive index of water with respect to air is $\frac{4}{3}$ . What is the refractive index of air with respect to water?

Answer 1

Step 1, Given data

Refractive index of water w.r.t air = $\frac{4}{3}$

Step 2,

We can write,

Refractive index of water w.r.t air

${\mu }_{wa}=\frac{{\mu }_w}{{\mu }_a}$ =$\frac{4}{3}$

We can also write,

${\mu }_{aw}=\frac{{\mu }_a}{{\mu }_w}$

From the above two equations we can say

${\mu }_{aw}=\frac{1}{{\mu }_{wa}}$

Putting all the values

${\mu }_{aw}=\frac{3}{4}$

Hence the refractive index of air w.r.t water = $\frac{3}{4}$