General Science
ID: #7005 | Difficulty: easy
AI Quick Answer:
The correct option for this defence exam question is (A) which is 340 m/s. Detailed proof and explanation are supplied below.
The speed of sound in air at 0°C is 331 m/s. What will be the speed of sound in air when the temperature increases to 15°C? (Assume speed increases by 0.6 m/s per degree Celsius).
Key Takeaways for NDA & CDS Candidates
- Ensure you recall the standard formulas for General Science during UPSC exam preparation.
- Eliminating obviously incorrect choices based on dimensional analysis or limits saves valuable seconds.
- Expert tip: Written defence mock tests should be practiced weekly with strict negative marking rules.
Correct Answer: (A)
340 m/s
Step-by-Step Explanation
Speed of sound increases with temperature according to the formula:
v = v_0 + 0.6 \times T
Where:
v_0 = 331 m/s (speed at 0°C)
T = 15°C (Temperature)
Substituting the values:
v = 331 + 0.6 \times 15 = 331 + 9 = 340 m/s.
v = v_0 + 0.6 \times T
Where:
v_0 = 331 m/s (speed at 0°C)
T = 15°C (Temperature)
Substituting the values:
v = 331 + 0.6 \times 15 = 331 + 9 = 340 m/s.
| Question Metadata Summary | |
|---|---|
| Exam Category | UPSC NDA / CDS / AFCAT / Agniveer |
| Subject Unit | Agniveer Questions |
| Sub-topic / Module | General Science |
| Correct Option | Option (A) |
| Target Year | UPSC Defence Exams 2026 |