Question

What is the principle of reversibility of light? show that the incident ray of light is parallel to the emergent ray of light 'yhen light falls obliquely on a side of a rectangular glass slab?

Answer 1

Principle of reversibility of light states that when the final path of a ray of light after any number of reflection and reflections is reversed the ray retrces its path

Answer 2

Light reverses it's path.