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
Verified Correct Answer: C.
Physical Principles & Numerical Solution
Angle of deviation = 180 - [i + v]
= 180 - 2i [since i = v]
∴ 120 = 180 - 2i
2i = 180 - 120
= 60
∴ i = 30o
Source: Myschool Past Questions Archive (Record #11712)