Question

Angle of glass prism is 60⁰ and refractive index of the material of the prism is 1.414,then what will be the angle of incidence, so that ray should pass symmetrically through prism

• A. 38⁰ 61'
• B. 35⁰ 35'
• C. 45⁰
• D. 53⁰ 8'

Answer 1

Answer: (C)

45⁰

Answer 2

Incident ray and emergent ray are symmetrical in the cure, when prism is in minimum deviation position.

Hence in this condition $\Rightarrow$ $\sin i = \mu \sin \left( \frac { A } { 2 } \right)$

$\Rightarrow$ $\sin i = 1.414 \times \sin 30 ^ { \circ } = \frac { 1 } { \sqrt { 2 } } \Rightarrow i = 45 ^ { \circ }$