A ray of light is incident on a plane mirror at an angle of 40° with respect to normal. When it gets reflected from the mirror, it undergoes a deviation of
40°
100°
90°
80°
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC CDS-2 – 2017
According to the law of reflection, the angle of incidence (i) is equal to the angle of reflection (r), and both are measured with respect to the normal to the mirror surface. Given i = 40°, then r = 40°. Deviation is the angle between the direction of the incident ray and the direction of the reflected ray. If the incident ray were not reflected, it would continue in a straight line. The reflection changes its direction.