Q. A ray of light falls on a transparent glass slab with refractive index (relative to air) of 1.62. The angle of incidence for which the reflected and refracted rays are mutually perpendicular is
A) $\tan^{- 1}{(1.62)}$
B) $\sin^{- 1}{(1.62)}$
C) $\cos^{- 1}{(1.62)}$
D) None of these
Explanation
(a) We know that
$\mu = \frac{\sin i}{\sin r}\ and\ \ i + r = 90{^\circ}$
Or $r = 90{^\circ} - i$
$\mu = \frac{\sin i}{\sin{(90{^\circ} - i)}}{= tan}i$
Or $\ i = \tan^{- 1}{(\mu) = \tan^{- 1}(1.62)}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.