Question

If the angle of incidence is 0°, what is the angle of deviation?

​

Answer 1

it will also be 0..............

Explanation: light will pass undeviated bcoz light ray is travelling perpendicular to the medium.

Answer 2

if the incident ray fall along the normal, the angle of incidence is 0° , not 90°> the angle is measured with the normal to the mirror and not with the plane of the mirror and not with the plane of the mirror. hence the angle of reflection is equal to 0°.