The formation of rainbow is an example of

The correct answer is Option (2) → Dispersion of light

Dispersion is the splitting of white light into its colours, because the refractive index of water is slightly different for each colour. A rainbow is a spectrum of sunlight formed in this way by raindrops: sunlight is refracted on entering a drop, the colours bend by different amounts, they are reflected inside the drop, and they are refracted again on leaving. The different colours then reach the eye from different directions, which is why we see them as separate bands.

Why the other options are incorrect

• Option (1) scattering of light — Incorrect. Scattering sends light in many directions and explains the blue sky and red sunset, not the coloured arc of a rainbow.

• Option (3) Refraction of light — Incorrect. Refraction takes place in the drop, but refraction alone would bend all colours equally and give only white light. It is the colour-dependent bending that forms the bow.

• Option (4) Total internal reflection — Incorrect. Reflection inside the drop is only one step on the path of the light; it does not separate the colours.

Note: This question is from the pre-rationalised NCERT book (2022-23). The topic was removed from the latest NCERT book (2026-27), and it also appears to be out of the CUET 2026 syllabus.

NCERT (Pre-rationalised edition, 2022-23):
The Rainbow – “… The rainbow is an example of the dispersion of sunlight by the water drops in the atmosphere. This is a phenomenon due to combined effect of dispersion, refraction and reflection of sunlight by spherical water droplets of rain.”