Q. A ray of light travelling inside a rectangular glass block of refractive index $\sqrt{2}$ is incident on the glass-air surface at an angle of incidence of $45{^\circ}$. The refractive index of air is 1. Under these conditions the ray
A) Will emerge into the air without any deviation
B) Will be reflected back into the glass
C) Will be absorbed
D) Will emerge into the air with angle of refraction equal to $90{^\circ}$
Explanation
(d) Since$\ _{a}\mu_{g} = \sqrt{2},$ so$\ _{g}\mu_{a} = \frac{\sin i}{\sin r} = \frac{1}{\sqrt{2}}$
$\therefore\sin r = 1 \Rightarrow r = 90{^\circ}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.