Question

A ray incident at a point at an angle of incidence of 60⁰ enter a glass sphere of refractive index $\sqrt { 3 }$ and is reflected and refracted at the farther surface of the sphere. The angle between the reflected and refracted rays at this surface is :

• A. 50⁰
• B. 60⁰
• C. 90⁰
• D. 40⁰

Answer 1

Answer: (C)

90⁰

Answer 2

: Refraction at P,

$\frac { \sin 60 ^ { \circ } } { \sin r _ { 1 } } = \sqrt { 3 }$

or

Since,

Refraction at or

Or $\mathrm { i } _ { 2 } = 60 ^ { \circ }$

At point

$\therefore \alpha = 180 ^ { \circ } - \left( \mathrm { r } _ { 2 } ^ { \prime } + \mathrm { i } _ { 2 } \right) = 180 ^ { \circ } - \left( 30 ^ { \circ } + 60 ^ { \circ } \right) = 90 ^ { \circ }$