Question

The refractive index of glass with respect to air is $3/2$. The refractive index of air with respect to glass will be :

• A. $1$
• B. $3/2$
• C. $2$
• D. $2/3$

Answer 1

The correct option is D $2/3$

${}^a{\mu }_g=\frac{n_g}{n_a}=\frac{3}{2}$ and ${}^g{\mu }_a=\frac{n_1}{n_2}=\frac{2}{3}$
If refractive index of glass w.r.t air is $3/2$, then refractive index of air w.r.t glass will be its reciprocal $2/3$.