Rainbow is produced when sunlight falls on drops of rain. Which of the following physical phenomena are responsible for this?
- 1.Dispersion
- 2.Refraction
- 3.Internal reflection
Select the correct answer using the code given below:
- A.1 and 2 only
- B.2 and 3 only
- C.1 and 3 only
- D.1, 2 and 3
▶ Answer & Explanation
Correct answer: D. 1, 2 and 3
Rainbow formation involves sunlight interacting with raindrops. Sunlight, which is white light, gets separated into its constituent colours (dispersion) as it enters a raindrop. The light then bends (refraction) as it enters the denser water. Subsequently, the light undergoes total internal reflection at the back surface of the raindrop. Finally, as the light exits the raindrop and re-enters the air, it refracts again, further separating the colours and making the spectrum visible.
Source: UPSC gs1 2013