Sample questions
You've seen the pattern — here are a few of the actual PYQs.
NDA2026
In a certain process, the relation between pressure (P) and volume (V), for an ideal gas, is given by PV² = constant. If the initial temperature is T₂ and the final temperature is T₂, and the initial volume is V₁ and the final volume is V₂, then which one of the following is correct?
- A T₁/T₂ = V₁/V₂
- B T₁/T₂ = (V₁/V₂)²
- C T₁/T₂ = V₂/V₁ ✓
- D T₁/T₂ = (V₂/V₁)²
✓ Correct answer: (C)
Science & Technology › Physics & Chemistry
NDA2026
For an ideal gas, a process is described by P = kT, where k is a constant. If the molar heat capacity for this process is C, then which one of the following is correct (where the symbols have their usual meanings)?
- A C = Cₚ
- B C = Cᵥ ✓
- C C = (Cₚ + Cᵥ)/2
- D C is never constant
✓ Correct answer: (B)
Science & Technology › Physics & Chemistry
NDA2026
A very large container consists of an ideal gas. The speed of sound in the gas is x. When the pressure of the gas is doubled while keeping the temperature constant, the speed of sound now becomes y. What is the ratio of x to y?
- A 1 ✓
- B √2
- C 2
- D 4
✓ 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 →