Question

The critical angle at an air-liquid interface is 50°. Calculate the refractive index of the liquid

Answer 1

Given:

$\theta_c=50^\circ$

The critical angle is given by

$$\sin\theta_c=\frac{1}{n}$$

Hence, he refractive index of the liquid

$$n=\frac{1}{\sin\theta_c}=\frac{1}{\sin50^\circ}=1.3$$