UPSC CSE Prelims
Question 2
Rainbow is produced when sunlight falls on drops of rain. Which of the following physical phenomena are responsible for this?
- Dispersion
- Refraction
- Internal reflection
Select the correct answer using the codes given below.
View correct answer and explanation
Correct answer: D
Correct Option: D
Explanation: A rainbow forms when sunlight enters raindrops, refracts and disperses into colours, reflects internally and refracts again on exit.
Statement/Pair-wise Analysis:
Statement/Item 1: Correct - Different wavelengths bend differently in water, separating white light into colours.
Statement/Item 2: Correct - Light refracts at the air–water boundary on entering and leaving a drop.
Statement/Item 3: Correct - Reflection within a droplet redirects the dispersed light towards the observer.
Option-wise Analysis:
A: Incorrect - excludes true item 3.
B: Incorrect - excludes true item 1.
C: Incorrect - excludes true item 2.
D: Correct - selects all and only the accurate statements/pairs.