Question

Light is incident on a glass surface at polarizing angle of $57.5^{\circ }$. Then the angle between the incident ray and the refracted ray is

• A. $57.5^{\circ }$
• B. $115^{\circ }$
• C. $205^{\circ }$
• D. $145^{\circ }$

Answer 1

Answer: (C)

When a light is incident at polarising angle, the reflected and refracted rays are perpendicular to each other as shown in the figure,

where $i_p$ is the angle of incidence and $r$ is the angle of reflection, $r^{\prime }$ is the angle of refraction.
Given, $i_p=57.5^{\circ }$
Let $\theta$ be the angle between the incident ray and the refracted ray.
From figure,
$\theta =i_p+r+90^{\circ }$
$=2i_p+90^{\circ }$
$=2\times 57.5^{\circ }+9{.}^{\circ }$
$=205^{\circ }[\because i_p=r]$