An engineer intends to deviate a light ray from its path by 120o through reflection from a plane mirror. Calculate the angle of incidence
-
A.
60o -
B.
40o -
C.
30o -
D.
20o
Correct Answer: Option C
Explanation
Angle of deviation = 180 – [i + v]
= 180 – 2i [since i = v]
∴ 120 = 180 – 2i
2i = 180 – 120
= 60
∴ i = 30o