Question

If a ray of light falls normally on a plane mirror how will it be reflected back? What will be the angle of incidence and angle of reflection

Answer 1

When a ray falls normally on the plane mirror, the angle with the normal is 0. Thus the angle of incidence is 0. So, laws of reflection, the angle of reflection is also 0. Thus, the ray retraces its path, i.e reflected normally from the plane mirror without any deviation.