An engineer intends to deviate a light ray from its path by 120degree through reflection from a plane mirror calculate the angle of incidence
Let's denote the angle of incidence as θ.
According to the law of reflection, the angle of incidence is equal to the angle of reflection. Since the engineer intends to deviate the light ray by 120 degrees, the angle of reflection will also be 120 degrees.
Therefore, we have:
θ + θ = 120 degrees
2θ = 120 degrees
Dividing both sides by 2:
θ = 60 degrees
So, the angle of incidence is 60 degrees.