UPSC Prelims 2013 · Question 22 of 99
UPSC Prelims 2013 question on Thunder Formation
- ExamUPSC CSE
- Year2013
- PaperGeneral Studies Paper I
- SubjectGeography
- TopicClimatology
- DifficultyHard
- TypeStatement
During a thunderstorm, thunder in the skies is produced by the:
1. Meeting of cumulonimbus clouds in the sky.
2. Lightning that separates the nimbus clouds.
3. Violent upward movement of air and water particles.
Select the correct answer using the codes given below:
Show answer
Answer: D. None of the above produces the thunder
Verdict
Correct Answer: None of the above
Analysis
According to the official UPSC Answer Key for Prelims 2013, the correct option is none of the above.
Thunder is not produced by the meeting of clouds or upward movement of air. It is produced by the sudden expansion of air heated by lightning.
1. Meeting of cumulonimbus clouds in the sky — Incorrect
Cumulonimbus clouds are associated with thunderstorms, but their meeting does not produce thunder.
Clouds consist of water droplets and ice crystals, and their collision does not directly create the sound of thunder.
This is not the physical cause of thunder.
2. Lightning that separates nimbus clouds — Incorrect
Lightning is an electrical discharge, but it does not “separate” clouds.
Thunder is caused by the rapid heating and expansion of air around lightning, not by cloud separation.
The statement describes the process incorrectly.
3. Violent upward movement of air and water particles — Incorrect
Strong updrafts help in thunderstorm formation and charge separation inside clouds.
However, the upward movement itself does not produce thunder.
It helps create conditions for lightning, but it is not the direct cause of thunder.
Extra UPSC info
* Thunder is a sound wave produced by the rapid expansion of air heated by lightning.
* Lightning can heat the surrounding air to extremely high temperatures in a very short time.
* The sudden expansion creates a shock wave, which is heard as thunder.
* Lightning is seen before thunder is heard because light travels much faster than sound.
* Cumulonimbus clouds are also called thunderclouds or thunderheads.
* Strong updrafts inside cumulonimbus clouds help in charge separation and lightning formation.
How to crack it
Thunder is produced by the shock wave from rapidly heated and expanding air around lightning, so none of the given options directly explains its cause.