Science Write notes.

(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 droplet present in the atmosphere, they refract and disperse the incident sunlight. That results in a spectrum.
(v) Then the light rays get reflected internally inside the droplet and finally again refract it.
(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.

(i) The process of separation of light into its component colours while passing through a medium is called dispersion of light.
(ii) Refractive index of a medium is different for different colours.
(iii) When white light enters a single medium like glass, the angles of refraction are different for different colours.
(iv) When white light from the sun through air, enters any refracting medium, it emerges as a spectrum of seven colours.
(v) Sir Issac Newton was the first person to use a glass prism to obtain sun’s spectrum.