Ans. REGULAR REFLECTION
The reflection of light in only one direction is called regular reflection.
For example, a smooth surface reflects the rays of light in one direction only. For regular reflection of light, the angle of incidence is equal to the angle of reflection
i.e. Zi = Zr.
IRREGULAR REFLECTION Fig. 12.2
The reflection of light in many directions is called irregular reflection. For example, a rough surface reflects the light rays in many directions.