A rainbow forms when sunlight passes through raindrops after a shower. Which combination of optical processes produces the coloured arc?
Q1. A rainbow forms when sunlight passes through raindrops after a shower. Which combination of optical processes produces the coloured arc?
Answer: Refraction on entering the drop, internal reflection at the back, and refraction again on exiting — separating white light into its constituent colours
Explanation: When a ray of sunlight enters a spherical raindrop, it refracts at the air-water boundary, reflects off the inside back surface, and refracts again as it exits; because the refractive index of water varies slightly with wavelength, different colours refract by different amounts, separating white light into a.