Question

A ray of light is travelling inside a rectangular glass block of refractive index $\sqrt{2}$ and incidents on glass-air interface at an angle of incidence 45${}^{\circ }$. Under these conditions, the ray

• A. will emerge into air with an angle of deviation $0$${}^{\circ }$
• B. will be reflected back into the medium
• C. will be absorbed
• D. will just graze the surface of seperation of the two media

Answer 1

The correct option is D will just graze the surface of seperation of the two media

$\mu sini=sinr$

$\sqrt{2}sin45=sinr$

=>$r={90}^{\circ }$

Therefore the angle of refraction is ${90}^{\circ }$.

So the ray will just graze the surface of separation of the two media.