Question

With respect to air, the refractive index of a flint glass and alcohol is $1.65$ and $1.36$ respectively. Calculate the refractive index of the flint glass with respect to alcohol.

Answer 1

Given:
Refractive index of flint glass with respect to air, $n_f=1.65$
Refractive index of alcohol with respect to air $n_a=1.36$

Let the refractive index of flint glass with respect to alcohol be $n_{fa}$.

From definition of refractive index,
$n_{fa}=\frac{n_f}{n_a}$
$n_{fa}=\frac{1.65}{1.36}=1.21$