Topic Optics
Asked 51 times across 6 UPSC exams over 47 years (1979–2026), peaking in 2022.
Key insights
- Most tested in CDS — 17 of 51 PYQs
- Most asked in 2022
- Recurs across 14 years (1979–2026)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CSE 1979 → CDS 2014 → CAPF 2018 → GEO 2021 → NDA 2021 → CISF 2022
How the concept evolved
179
180
188
194
214
216
318
419
721
1122
323
624
825
126
Rising — more than half its appearances (45 of 51) 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.
CDS2026
An object is placed at a distance of 15 cm in front of a concave mirror with a radius of curvature of 20 cm. Which one among the following statements is correct for the image formed ?
- A The image is 30 cm from the mirror on the same side as the object. ✓
- B The image is formed at a distance of 30 cm behind the mirror.
- C The image is 60 cm from the mirror on the same side as the object.
- D The image is formed at a distance of 60 cm behind the mirror.
✓ Correct answer: (A)
Science & Technology › Physics & Chemistry
CAPF2025
When sunlight (white light) falls on a triangular glass prism, a band of colours called a spectrum is obtained. Which one among the following represents this effect appropriately?
- A Reflection
- B Diffraction
- C Refraction
- D Dispersion
Answer key not yet available (pending official release)
Science & Technology › Physics & Chemistry
CAPF2025
Which one among the following statements related to human eye is correct?
- A For a person suffering from short-sight defect, the image of a distant object is focused behind the retina.
- B Short-sight defect can be corrected by a converging spectacle lens.
- C For a person suffering from long-sight defect, the image of a near object is focused behind the retina.
- D Long-sight defect can be corrected by a diverging spectacle lens.
Answer key not yet available (pending official release)
Science & Technology › Physics & Chemistry
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