Q. The wavelength of light in two liquids ‘$x$’ and ‘$y$’ is 3500 $\mathring{\mathrm{A}}$ and 7000 $\mathring{\mathrm{A}}$, then the critical angle of $x$ relative to $y$ will be
A) $60{^\circ}$
B) $45{^\circ}$
C) $30{^\circ}$
D) $15{^\circ}$
Explanation
(c) The critical angle $C$ is given by
$\sin C = \frac{n_{2}}{n_{1}} = \frac{\lambda_{1}}{\lambda_{2}} = \frac{3500}{7000} = \frac{1}{2} \Rightarrow C = 30{^\circ}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.