Question

(a) Why are some surfaces shiny, whereas others' aren't?

(b) How is Rainbow formed?
[3 MARKS]

Answer 1

(a) Explanation: 2 Marks
(b) Explanation: 1 Mark

(a) Shiny objects are those that reflect most of the light that falls on them. Only those substances which have a smooth surface can be shiny. This is because smooth surfaces reflect light uniformly in a particular direction. Because of this, almost all of the light that falls on them get reflected collectively without any considerable loss.

Objects which are not shiny have rough surfaces. When light falls on these rough surfaces, the light get reflected in a random direction, leading to loss in intensity. Hence, such substances are not considered shiny.


(b) Light is made up of seven colours. When the sun shines after the rain and sunlight passes through suspended raindrops this white light from the sun splits into seven constituent colours "VIBGYOR”, which we see as rainbow