Rainbow formation or Prove that a rainbow is the combined effect of the refraction, dispersion and total internal reflection of light.

Explanation

(i) The beautiful phenomenon of the rainbow is a combination of different phenomena namely dispersion of light, internal reflection and refraction of light.
(ii) The rainbow appears in the sky after a rain shower.
(iii) The water droplets act as small prisms.
(iv) When sunlight enters the water droplets present in the atomosphere, they refract and disperse teh incident sunlight. That results in a spectrum.
(v) Then teh light rays get reflected internally inside the droplet and finally again get refracted.
(vi) As a collective effect of all these phenomena, the seven coloured rainbow is observed.
(vii) In the morning, rainbow can be seen towards west, while in the evening, it can be seen towards the East.