Sample questions
You've seen the pattern — here are a few of the actual PYQs.
CDS2023
Which of the following statements are true for the reaction of Fe2O3 with aluminium?
- It is known as the 'thermite reaction'
- The heat evolved is used for welding purpose
- Aluminium metal acts as an oxidizing agent
- Molten Fe and Al are formed at the end of the reaction
Select the correct answer using the code given below.
- A 1 and 2 ✓
- B 1 and 3
- C 2 and 4
- D 1 and 4
✓ Correct answer: (A)
Science & Technology › Physics & Chemistry
CDS2022
In the joining of railway tracks, iron oxide is made to react with
- A Aluminium ✓
- B Zinc
- C Copper
- D Tin
✓ 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 →