Question

What is reflection? Write a short note on regular and irregular reflection.

Answer 1

A ray of light, falling on a body having a shiny polished and smooth surface alone is bounced back. This bouncing back of the light rays as they fall on the smooth, shiny, and polished surface is called reflection.

• Regular reflection:

1. When a beam of light (collection of parallel rays) falls on a smooth surface, it gets reflected.
2. After reflection, the reflected rays will be parallel to each other. Here, the angle of incidence and the angle of reflection of each ray will be equal.
3. Hence, the law of reflection is obeyed in this case and thus a clear image is formed. This reflection is called ‘regular reflection’ or ‘specular reflection’.

• Irregular reflection:

1. In the case of a body having a rough or irregular surface, each region of the surface is inclined at different angles.
2. When light falls on such a surface, the light rays are reflected at different angles.
3. In this case, the angle of incidence and the angle of reflection of each ray are not equal.
4. Hence, the law of reflection is not obeyed in this case and thus the image is not clear. Such a reflection is called ‘irregular reflection’ or ‘diffused reflection’.