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Physics

Electromagnetic Waves

A Physics chapter of the NEET syllabus, and how to practise it for the computer-based exam.

Exam rules change between cycles. Confirm dates, syllabus and pattern against NTA's official site. We are not NTA.

Weightage: what the paper actually did

Electromagnetic Waves carried 3 questions in the NEET 2026 paper. One paper is a data point, not a destiny: NTA moves weight between chapters every cycle, which is why the weightage tables deserve care. The stable facts are the paper's shape: 180 questions, 720 marks, +4 right, −1 wrong.

Sample PYQs from this chapter

Real questions NTA asked from Electromagnetic Waves, with the answer and the working. Try before you peek.

Question 1 · NEET 2026

An electromagnetic wave travelling in a lossless dielectric medium having a dielectric constant, εr=9\varepsilon_r = 9, has the electric field, Ex=E0sin⁡(kz−2π×106t) Vm−1E_x = E_0\sin(kz - 2\pi \times 10^6 t)\ \text{Vm}^{-1} where E0E_0 is the amplitude and kk is the wave vector. Among the following options, the incorrect choice is
  1. A.The speed of the electromagnetic wave inside the medium is 108 ms−110^8\ \text{ms}^{-1}
  2. B.The wavelength of the electromagnetic wave inside the medium is 300 m
  3. C.The magnetic field is given by the relation By=B0vsin⁡(kz−2π×106t)B_y = \frac{B_0}{v}\sin(kz - 2\pi \times 10^6 t) where vv is the speed of the electromagnetic wave inside the medium
  4. D.The direction of propagation of the electromagnetic wave is along +z+z
Answer and explanation

Answer: B or C (NTA awarded marks for both)

Official-key note: NTA accepted both B and C; B is retained as the primary/intended answer. The refractive index is n=εr=3n = \sqrt{\varepsilon_r} = 3, so v=cn=108 m s−1v = \frac{c}{n} = 10^8\ \text{m s}^{-1}, making A correct. From ω=2π×106\omega = 2\pi \times 10^6, the frequency is 106 Hz10^6\ \text{Hz}, hence λ=vf=100 m\lambda = \frac{v}{f} = 100\ \text{m}, not 300 m; therefore B is incorrect. C is also incorrect as printed: the magnetic field should be By=E0vsin⁡(kz−ωt)B_y = \frac{E_0}{v}\sin(kz-\omega t), whereas the option uses B0/vB_0/v. D is correct because kz−ωtkz-\omega t represents propagation along +z+z. NCERT Class 12, Electromagnetic Waves.

Question 2 · NEET 2020

Light with an average flux of 20 W cm−^{-}2^{2} falls on a non-reflecting surface at normal incidence having surface area 20 cm2^{2}. The energy received by the surface during a time span of 1 minute is
  1. A.12 * 103^{3} J
  2. B.24 * 103^{3} J
  3. C.48 * 103^{3} J
  4. D.10 * 103^{3} J
Answer and explanation

Answer: B

The energy received is given by E = flux * area * time. Substituting, E=20 W/cm2∗20 cm2∗60 s=24∗103 JE = 20\ W/cm^2 * 20\ cm^2 * 60\ s = 24 * 10^3\ J. Chapter: Electromagnetic Waves.

How to practise Electromagnetic Waves

Chapter by chapter, against real past-paper questions, on a screen: NEET is computer based from 2027. Read the chapter once, then attempt its PYQs until your accuracy stops climbing, and let the wrong answers tell you which lines to reread. If the chapter keeps refusing to stick, that has its own guide. There is also a free NEET mini mock with answers.

Nearby Physics chapters

Questions

How many questions did Electromagnetic Waves have in NEET 2026?

Electromagnetic Waves carried 3 questions in the NEET 2026 paper. Weightage shifts between cycles, so treat it as a probability, not a promise.

Where can I practise Electromagnetic Waves PYQs for NEET?

Explore available chapter-wise NEET practice in BrainIt, free until the 2027 exam. Review explanations and track chapter accuracy to guide your revision. Sample questions from this chapter are on this page.

Is Electromagnetic Waves important for NEET 2027?

It is part of the Physics syllabus the paper draws from, and NEET 2027 is computer based, so practise it on a screen. Your own accuracy in the chapter matters more than any weightage table: a heavy chapter you already score well on needs less time than a light one you keep missing.

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