Sample questions
You've seen the pattern — here are a few of the actual PYQs.
GEO2025
The radius of the first stationary orbit of hydrogen atom is
- A 5·0 Å
- B 52·9 pm ✓
- C 5·29 pm
- D 0·529 pm
✓ Correct answer: (B)
Science & Technology › Physics & Chemistry
GEO2023
The radius of the first orbit (n =
- of a hydrogen atom is 0·529 Å. Then the radius of the second orbit (n =
- of He⁺ ion will be
- A 1·058 Å ✓
- B 2·116 Å
- C 4·232 Å
- D 0·529 Å
✓ 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 →