A ray of light incident at 25° on one refracting surface of a prism of angle 60° suffers a deviation of 50°. What will be the angle of emergence?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 85°
Given:
Angle of incidence: $i = 25^\circ$
Prism angle: $A = 60^\circ$
Deviation: $\delta = 50^\circ$
Relation between deviation, prism angle, and angles of incidence and emergence:
$\delta = i + e - A \Rightarrow e = \delta + A - i$
Substitute values:
$e = 50 + 60 - 25 = 85^\circ$
∴ Angle of emergence = 85°