ICSE Class 9 Answered

1. When a beam of light falls on a smooth and polished surface (say a plane mirror, glass, or water), regular reflection occurs.  
2. 
3. The incident rays and reflected rays are parallel beams.
4. We find our images in proper proportions in plane mirrors due to regular reflection.
5. The reflected ray of light moves only in a fixed direction.
6. Images formed by regular reflection are always clear and distinct.
7. This property of light is used in search light.

Irregular/Diffused reflection:

1. When a beam of light falls on a rough surface (say a wall, plastic sheets, writing paper, wooden boards, cloths, skin, leather pieces, or a road), irregular reflection occurs.
2. 
3. The walls may appear smooth, but if observed under a microscope, they appear uneven with crater-like projections.
4. The diffused rays after reflection scatter in different directions.
5. The incident rays are parallel beams, but the light reflected from different surfaces will reflect at different angles obeying the laws of reflection.
6. Due to irregular reflection, we are able to see things around us.