Topic Corrosion
Asked 9 times across 2 UPSC exams over 9 years (2014–2023), peaking in 2021.
Key insights
- Most tested in CDS — 6 of 9 PYQs
- Most asked in 2021
- Recurs across 5 years (2014–2023)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CDS 2014 → NDA 2021
How the concept evolved
Rising — more than half its appearances (8 of 9) 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.
CDS2023
Which one of the following is not true for anodizing process?
- A It makes aluminium corrosion resistant.
- B Metals like aluminium, titanium and magnesium can be anodized.
- C Clean aluminium article is the anode and oxygen gas is evolved at the cathode. ✓
- D It is used in aircraft industry.
✓ Correct answer: (C)
Science & Technology › Physics & Chemistry
NDA2023
Galvanization is a method of protecting iron from rusting by coating with a thin layer of
- A Gallium
- B Aluminum
- C Zinc ✓
- D Silver
✓ Correct answer: (C)
Science & Technology › Physics & Chemistry
NDA2022
Silver artefacts get tarnished in air due to the formation of
- A silver chloride
- B silver oxide
- C silver sulphide ✓
- D silver sulphate
✓ Correct answer: (C)
Science & Technology › Physics & Chemistry
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