Lakhmir Singh and Manjit Kaur Solutions for Chapter: Light, Shadows, and Reflections, Exercise 5: Questions Based on High Order Thinking Skills (HOTS)

What is the colour of shadow formed:

(a) if the colour of object is white?
(b) if the colour of object is red?

There are three materials A, B and C. When material A is held in front of our eyes, we cannot see anything at all. But when material B is held in front of our eyes, we can see everything through it clearly. On the other hand, when material C is held in front of our eyes, we can see through it only faintly, but not clearly.

(a) Which material is (i) transparent (ii) opaque, and (iii) translucent?

(b) Name one material each which behaves like (i) A (ii) B, and (iii) C.

On a sunny day, when we pass under a tree covered with a very large number of leaves, we often see bright circular patches of light on the ground (under the tree).

(a) What are the bright circular patches of light?
(b) Name the object (source of light) in this case.
(c) What acts as screen in this case?
(d) Which effect is illustrated by the everyday observation described above?

A tall device which contains plane mirrors can be used to see over the heads of crowd (say, as in a football match).

(a) What is the name of this device?

(b) How many plane mirrors does it use?

(c) On what principle does this device work?

A man is sitting on a chair in a dark room near one of the walls. A big mirror is hung on the wall facing the man. When a torchlight is put on the man from a distance, then we can see X of the man on the wall behind him. At the same time, Y of the man can be observed in the mirror on the wall.

(a) What is X?

(b) What is Y?

(c) State one way in which X differs from Y.