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Topic Speed of sound
Asked 3 times across 2 UPSC exams over 3 years (2020–2023), peaking in 2020.
Key insights
- Most tested in CDS — 2 of 3 PYQs
- Most asked in 2020
- Recurs across 3 years (2020–2023)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CDS 2020 → NDA 2022
How the concept evolved
Rising — more than half its appearances (3 of 3) are since 2016.
Related concepts
Ideas UPSC tests alongside this one — keep exploring.
Sample questions
You've seen the pattern — here are a few of the actual PYQs.
CDS2023
Sonic boom is produced when a source of sound travels at a speed :
- A greater than the speed of sound. ✓
- B greater than the speed of light.
- C lesser than the speed of sound.
- D equal to the speed of sound.
✓ Correct answer: (A)
Science & Technology › Physics & Chemistry
NDA2022
Which one of the following statements about the speed of sound waves is not correct?
- A The speed of sound waves in steel is higher than that in water.
- B The speed of sound waves in air decreases with increase in temperature. ✓
- C The speed of sound waves in air increases with increase in temperature.
- D The speed of sound waves in water is higher than that in air.
✓ Correct answer: (B)
Science & Technology › Physics & Chemistry
CDS2020
Which one of the following phenomena verifies the fact that light travels much faster than sound?
- A Twinkling of stars in night sky
- B Lighting of a matchstick
- C Thunderstorm ✓
- D Mirage
✓ Correct answer: (C)
Science & Technology › Physics & Chemistry
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