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°
For refraction through a prism, the angle of deviation is related to the angle of incidence \( i \), the angle of emergence \( e \) and the angle of the prism \( A \) by
\( \displaystyle \delta = i + e - A \)
\( i = 25^\circ \)
\( A = 60^\circ \)
\( \delta = 50^\circ \)
\( \displaystyle e = \delta + A - i = 50^\circ + 60^\circ - 25^\circ = 85^\circ \)