Home / Topic / Oscillations
Topic Oscillations
Asked 3 times across 2 UPSC exams over 2 years (2024–2026), peaking in 2025.
Key insights
- Most tested in NDA — 2 of 3 PYQs
- Most asked in 2025
- Recurs across 3 years (2024–2026)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CISF 2024 → NDA 2025
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.
NDA2026
A pendulum of length L oscillates with an angular amplitude of θ = 60° and time period T. Let T₀ = 2π√(L/g) be the time period for small angle of oscillations, where g is the acceleration due to gravity. If air resistance is negligibly small and the string remains straight, then which one of the following is correct?
- A T will be slightly greater than T₀. ✓
- B T will be slightly smaller than T₀.
- C T will be exactly equal to T₀.
- D T will depend upon the mass of the bob.
✓ Correct answer: (A)
Science & Technology › Physics & Chemistry
NDA2025
The length of a simple pendulum is increased four times to its previous value while the mass is doubled. What is the ratio of the new and previous time period of the pendulum?
- A 3 : 1
- B 2 : 5
- C 2 : 1 ✓
- D 3 : 2
✓ Correct answer: (C)
Science & Technology › Physics & Chemistry
CISF2024
What is the length of a simple pendulum, which has a frequency of 0·5 Hz (take g = 10 m/s^2)?
- A 1 m ✓
- B 2 m
- C 1·5 m
- D 3 m
✓ Correct answer: (A)
Science & Technology › Physics & Chemistry
Study how UPSC repeats — not just the papers
₹199 / 1 year · Founding Member
Full access unlocks the three things no PYQ PDF gives you:
① Cross-exam learning — see the same idea recur across CSE, CAPF, CDS and NDA.
② Topic evolution — how each idea is framed, year by year.
③ Question intelligence — every PYQ + answer, linked to related concepts and similar questions.
e.g. Round Table Conference: CDS 2017 → CSE 2017 → … → CAPF 2024
15 days free, no card required — then ₹199 for 1 year.
Start your 15-day free trial →