Question

If the light ray traces the path shown in the figure,Find the angle of incidence.

Answer 1

Let,
Angle of incidence $=i$
Angle of refraction $=r$

from the figure,
$\sin r=\frac{\text{AB}}{\text{OA}}$

AB $=4\text{m}$
OA = $\sqrt{4^2+4^2}=4\sqrt{2}$ m
$\sin r=\frac{\text{4}}{4\times \sqrt{2}}$

$r={45}^{\circ }$

According to Snell's law,
$n_1\sin i=n_2\sin r$
$\sin i=\frac{n_2}{n_1}\times \sin r$
$\sin i=\frac{1.22}{1}\times \sin 45$
$=\frac{1.22}{\sqrt{2}}$
$=0.866$
Therefore,
$i={60}^{\circ }$