Q. A ray of light travels from an optically denser to rarer medium. The critical angle for the two media is $C$. The maximum possible deviation of the ray will be
A) $\left( \frac{\pi}{2} - C \right)$
B) $2C$
C) $\pi - 2C$
D) $\pi - C$
Explanation
(c) When the ray passes into the rarer medium, the deviation is $\delta = \phi - \theta$. This can have a maximum value of $\left( \frac{\pi}{2} - C \right)$ for $\theta = C$ and $\phi = \frac{\pi}{2}$
When total internal reflection occurs, the deviation is $\delta = \pi - 2\theta$, the minimum value of $\theta$ being $C$. The maximum value of $\delta = \pi - 2C$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.