Question

A ray of light is incident ( perpendiculuarly) on a plane mirror. Where willbthiscray of light go after reflection from the mirror ?

Answer 1

We know that Angle of Incidence = Angle of Reflection,

We usually calculate this angle with reference to Normal ray,
And also the Normal ray is always perpendicular to the plane mirror,

So by this we can say that Light ray makes 0° with normal ray, i.e it is perpendicular to the plane mirror,

By the laws of reflection, We can say that reflected ray also should make 0° with normal ray, So it also has to be perpendicular with plane mirror,

So By this we can say that Reflected ray travels the same path from where incident ray come from, So literally, It re-traces it's path,

Hope you understand , Have a great day !

Answer 2

The reflected ray will go in the same direction as the incident ray as the angle of incidence is 90 degrees.