Question #2e7e3
1 Answer
When light or some electromagnetic wave enters a a medium from another, it's velocity changes. Due to that change in velocity, the light ray slightly bends from it's regular path.
This is called refraction.
Explanation:
The speed of light in some medium is given in terms of electric and magnetic properties (permittivity and permeability) of that medium.
But, we are getting ahead of ourselves and let us for now return to the original question.
When light enters a optically denser medium from an optically rarer medium (denser in the sense that, the velocity of light is lesser in the new medium), light bends towards the normal drawn at the point light enters the new medium.
The opposite is true when light enters an optically rarer medium : the ray bends away from the normal.
The above results can be proved considering light to be a wave using the Huygen's principle.
The bending of a ray of light when it goes from one medium to another of different optical density, is called refraction.
