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Topic Energy conservation
Asked 3 times across 3 UPSC exams over 9 years (2015–2024), peaking in 2015.
Key insights
- Most tested in CDS — 1 of 3 PYQs
- Most asked in 2015
- Recurs across 3 years (2015–2024)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CDS 2015 → GEO 2021 → NDA 2024
How the concept evolved
Rising — more than half its appearances (2 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.
NDA2024
There is a ball of mass 320 g. It has 625 J potential energy when released freely from a height. The speed with which it will hit the ground is
- A 62.5 m/s ✓
- B 2.0 m/s
- C 50 m/s
- D 40 m/s
✓ Correct answer: (A)
Science & Technology › Physics & Chemistry
GEO2021
A stone of mass 1 kg and initially at rest is dropped from a tower of height 40 m. When it reaches a height of 10 m from the ground level, what will be the values of its potential energy (PE) and kinetic energy (KE)? (Acceleration due to gravity is 10 m/s²)
- A PE = 300 J, KE = 100 J
- B PE = 200 J, KE = 200 J
- C PE = 100 J, KE = 300 J
- D PE = 100 J, KE = 200 J
Answer key not yet available (pending official release)
Science & Technology › Physics & Chemistry
CDS2015
An object is raised to a height of 3 m from the ground. It is then allowed to fall on to a table 1 m high from ground level. In this context, which one among the following statements is correct ?
- A Its potential energy decreases by two-thirds its original value of total energy. ✓
- B Its potential energy decreases by one-third its original value of total energy.
- C Its kinetic energy increases by two-thirds, while potential energy increases by one-third.
- D Its kinetic energy increases by one-third, while potential energy decreases by one-third.
✓ Correct answer: (A)
Science & Technology › Physics & Chemistry
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