A ray of light in air is occurrence upon a flat piece of glass. How acts the path that the light travels along when it is in the glass compare with the path in the air?

Ans:

The phrase utilize to memorize this fact is on going from less dense to more dense the light is bent toward the normal. While this is a helpful memory device it should not be taken too literally. For one thing mass density isn't relevant. The phrase dense in this context refers to optical density which is an expression sometimes used to characterize a transparent material. A material that is smaller optically dense than another material is actually one that has a smaller index of refraction. A material that is further optically dense than another material is actually one that has a greater index of refraction. Next light isn't something that can be bent. The bent part refers to the reality that when light that is travelling in a transparent medium with one index of refraction passes through an interface between that transparent medium and a transparent medium with a greater index of refraction the light which had been travelling along one straight line path abruptly at the interface adopts a new straight line path a path that makes a smaller angle with the normal. The usual is an imaginary line perpendicular to the interface and passing through the interface at the point at which the incident ray hits the interface.