Question

A ray of light is incident of the surface of a glass plate at an angle of incidence equal to Brewster's angle \(\Phi\). If \(μ\) denotes the refractive index of glass w.r.t. air, then what will be the angle between reflected and refracted rays?

• A. \(90^{\circ}-sin^{-1}(sin\Phi /μ)\)
• B. \(90^{\circ}\)
• C. \(sin^{-1}(μcos\Phi )\)
• D. \(90^{\circ}+\Phi\)

Hint:

At Brewster angle the reflected and refracted rays are perpendicular.

Answer 1

The Correct Option is B

Step 1: Brewster law
At the polarising angle, \(\tan\Phi=\mu\), and \(\Phi+r=90^{\circ}\).

Step 2: Angle between rays
The reflected ray makes \(\Phi\) with the normal and the refracted ray makes \(r=90^{\circ}-\Phi\). The angle between them is \(180^{\circ}-\Phi-r=90^{\circ}\). Option (B).

Final Answer:
The angle is \(90^{\circ}\), option (B). \[ \boxed{\text{(B) }90^{\circ}} \]