JEE Main 2026 — Electromagnetic Waves Question with Solution
JEE Main 2026 (22 January Shift 1)
Question
The electric field of a plane electromagnetic wave, travelling in an unknown nonmagnetic medium is given by, (where and other values have S.I. units). The dielectric constant of the medium is (speed of light in free space is )
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Show full solutionCorrect answer: 4
Correct answer
4
Step-by-step explanation
From the wave equation :
Wave number: m⁻¹
Angular frequency: rad/s
Speed of wave in medium: m/s
Speed of light in vacuum: m/s
Refractive index:
For a nonmagnetic medium:
Dielectric constant:
Wave number: m⁻¹
Angular frequency: rad/s
Speed of wave in medium: m/s
Speed of light in vacuum: m/s
Refractive index:
For a nonmagnetic medium:
Dielectric constant:
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This is a previous-year question from JEE Main 2026, covering the Electromagnetic Waves chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.