What is a prism ? Draw a ray diagram to show the refraction of a light ray through a prism.

(b) Rainbow is an arch of seven colours visible in the sky which is produced by the dispersion of sun's light by raindrops in the atmosphere. A rainbow is formed in the sky when the sun is shining and it is raining at the same time.

(c) Raindrops

(d) Dispersion of light

(e) Red, Orange, Yellow, Green, Blue, Indigo and Violet.