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Topic Dispersion
Asked 4 times across 4 UPSC exams over 8 years (2014–2022), peaking in 2014.
Key insights
- Most tested in CDS — 1 of 4 PYQs
- Most asked in 2014
- Recurs across 4 years (2014–2022)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CDS 2014 → EPFO 2015 → NDA 2021 → GEO 2022
How the concept evolved
Long-running — most appearances (2 of 4) predate 2016, and it still returns.
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.
GEO2022
The refractive index of a prism made of flint glass is
- A the same for all wavelengths in white light
- B higher for red light than for violet light
- C higher for violet light than for red light ✓
- D highest for green and yellow lights and lowest for violet and red lights
✓ Correct answer: (C)
Science & Technology › Physics & Chemistry
NDA2021
A glass prism splits white light into different colours. This phenomenon is called dispersion of light by prism. Which one of the following statements is correct ?
- A Red light will deviate the most and it is because of the reflection of light.
- B Violet light will deviate the most and it is because of the refraction of light. ✓
- C Red light will deviate the most and it is because of the refraction of light.
- D Violet light will deviate the most and it is because of the reflection of light.
✓ Correct answer: (B)
Science & Technology › Physics & Chemistry
EPFO2015
Which of the following is not an absolute measure of dispersion ?
- A Range
- B Mean Deviation
- C Quartile Deviation
- D Coefficient of Variation ✓
✓ Correct answer: (D)
Quantitative Aptitude › Data Sufficiency
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