Question

Aray of light makes an angle of 10° with the horizontal above it and strikes a plane mirror which is inclined at an angle O to the horizontal. The angle O for which the reflected ray becomes vertical is 10 degree

Answer 1

Angle between the reflected and incident ray = 80 (Final ray is vertical and incidence is 10 wrt horizontal)
Angle of incidence = angle of reflected ray = 40
Angle of reflected ray with mirror = 90 – 40 = 50
So, angle with horizontal = 90 – 50 = 40

Answer 2

Answer
the reflected and incident ray = 80 (Final ray is vertical and incidence is 10 wrt horizontal)
Angle of incidence = angle of reflected ray = 40
Angle of reflected ray with mirror = 90 – 40 = 50
So, angle with horizontal = 90 – 50 = 40
Thank you