Explain: ‘How is a rainbow formed’?


1.  The beautiful phenomenon of the rainbow is a combination of different phenomena – dispersion, refraction and reflection of light.
2.  The rainbow appears in the sky after a rain shower.
3.  The water droplets act as small prisms.
4.  When sunlight enters the water droplets present in the atmosphere, they refract and disperse the incident sunlight.
5.  Then they reflect it internally inside the droplet and finally again refract it.
6.  As a collective effect of all these phenomena, the seven coloured rainbow is observed.