Question

Mention against each of the following whether regular or diffused reflection will take place when a beam of light strikes. Justify your answer in each case.
(a) Polished wooden table
(b) Chalk powder
(c) Cardboard surface
(d) Marble floor with water
(e) Mirror
(f) Piece of paper

Answer 1

Hint Regular Reflection
1. Reflection from a polished surface is called regular reflection.
2. Parallel rays remain parallel after reflection.
Irregular Reflection:
1. Reflection from a rough surface is called diffuse reflection.
2. Parallel rays do not remain parallel after reflection.

Step by step solution
As we know that Regular reflection occurs at perfectly smooth surfaces and diffused reflection occurs at rough surfaces.

(a). Polished wooden table: Regular reflection - A polished surface is an example of a smooth surface. A polished wooden table has a smooth surface. Hence, reflections from the polished table will be regular.

(b). Chalk powder: Diffused reflection - Chalk powder spread on a surface is an example of an irregular surface. It is not smooth. Therefore, diffused reflection will take place from chalk powder.

(c). Cardboard surface: Diffused reflection - Cardboard surface is also an example of an irregular surface. Hence, diffused reflection will take place from a cardboard surface.

(d). Marble floor with water spread over it: Regular reflection - Marble floor with water spread over it is an example of a regular surface. This is because water makes the marble surface smooth. Hence, regular reflection will take place from this surface.

(e). Mirror: Regular reflection - Mirror has a smooth surface. Therefore, it will give a regular reflection.

(f). Piece of paper: Diffused reflection - Although a piece of paper may look smooth, but it has many irregularities on its surface. Due to this reason, it will give a diffused reflection.

Note
Reflection is an instance of reflecting; especially: the return of light or sound waves from a surface.
Regular reflection 

Diffuse reflection: