Question

A ray of light $\left(R_{1}\right)$ is incident on a glass slab at an angle equal to critical angle of glass-air system. The refracted ray $\left(R_{2}\right)$ undergoes partial reflection and refraction at other surface of slab. The angle between the reflected ray $\left(R_{3}\right)$ and refracted ray $\left(R_{4}\right)$ is

• A. $45^{\circ} $
• B. $135^{\circ }$
• C. $105^{\circ} $
• D. $95^{\circ} $

Answer 1

Answer: (C)

$\frac{\sin 45^{\circ}}{\sin \theta}=\sqrt{2}$
$\theta=30^{\circ}$
$\alpha=180^{\circ}-\left(30^{\circ}+45^{\circ}\right)=105^{\circ}$