Question

If the refractive index of a dense flint glass is $1.65$ and of alcohol is $1.36$ with respect to air, then the refractive index of the dense flint glass with respect to alcohol is

• A. 1.31
• B. 1.21
• C. 1.11
• D. 1.01

Answer 1

The correct option is B

1.21

Refractive index of the 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: $n_{fa}$
$\therefore n_{fa}=\frac{n_f}{n_a}=\frac{1.65}{1.36}=1.21$