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Topic Electromagnetic waves
Asked 9 times across 5 UPSC exams over 41 years (1985–2026), peaking in 2019.
Key insights
- Most tested in GEO — 4 of 9 PYQs
- Most asked in 2019
- Recurs across 8 years (1985–2026)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CSE 1985 → CAPF 2019 → CDS 2020 → GEO 2021 → NDA 2026
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.
NDA2026
With respect to electromagnetic waves, the human eye is sensitive to
- A both electric and magnetic fields
- B electric field only ✓
- C magnetic field only
- D infrared part of the electromagnetic spectrum
✓ Correct answer: (B)
Science & Technology › Physics & Chemistry
GEO2025
An electromagnetic wave with its magnetic field B = 0.3cos(8y - 10^8 t) ĵ tesla is propagating in a non-magnetic dielectric medium of refractive index 2. The wavelength of the wave is
- A 6π m
- B 3π m ✓
- C 0.3 m
- D (2π/3) m
✓ Correct answer: (B)
Science & Technology › Physics & Chemistry
GEO2024
At a given point in space, the electric field associated with an electromagnetic wave is given by E = (2 î − 1·5 ĵ) e^(ik(2t + 4y) − ωt). At the same point, which one among the following is the correct value of the unit vector (B̂) of the magnetic field associated with this electromagnetic wave ?
- A − k̂ ✓
- B 1·6 î + 2 ĵ
- C 1·5 î − 2 ĵ
- D 3 î − 4 ĵ
✓ Correct answer: (A)
Science & Technology › Physics & Chemistry
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