Ans. REFRACTION OF LIGHT
The process of bending of light as it passes from air into glass and vice versa is called refraction of light.
Refraction of light can be explained with the help of Fig. 12.3. A ray of light IO travelling from air falls on the surface of a parallel-sided glass block.
At the air-glass interface, the ray of light IO changes direction and bends towards the normal and travels along the path OR inside the glass block. When refracted ray leaves the glass, ft bends away from the normal and travels along the path MF. This is called refraction of light.