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Friday, 9 October

NEET UG 2026 · Physics · Question 38

NEET 2026 Physics, question 38

Question 38 of the NEET 2026 paper (re-exam) is a Physics question from Electromagnetic Waves. Its idea, Speed of EM Waves, was asked twice, in 2022 and 2026, across NEET 2017–2026. The NTA final answer key gives options 2 and 3 (the key accepted both).

Updated 2026-10-08

Q38 · Physics

An electromagnetic wave travelling in a lossless dielectric medium having a dielectric constant, ϵr=9\epsilon_r=9, has the electric field, Ex=E0sin⁡(kz−2π×106t)E_x=E_0\sin(kz-2\pi\times10^6t) Vm−1^{-1} where E0E_0 is the amplitude and k is the wave vector. Among the following options, the incorrect choice is :

  1. 1The speed of the electromagnetic wave inside the medium is 10810^8 ms−1^{-1}
  2. 2The wavelength of the electromagnetic wave inside the medium is 300 mOfficial answer
  3. 3The magnetic field is given by the relation By=B0vsin⁡(kz−2π×106t)B_y=\frac{B_0}{v}\sin(kz-2\pi\times10^6t) where vv is the speed of the electromagnetic wave inside the mediumOfficial answer
  4. 4The direction of propagation of the electromagnetic wave is along +z

Official answer: options 2 and 3 · NTA final answer keyThe key accepted more than one option for this question.

Same idea

Speed of EM Waves, in other papers

NEET asked this idea twice, in 2022 and 2026. The other question below.

  • 2022 Q11When light propagates through a material medium of relative permittivity ϵr\epsilon_r and relative permeability μr\mu_r, the velocity of…One-line MCQ · Easy

Speed of EM Waves: every question and how it was framed

The chapter

Electromagnetic Waves in ten years of NEET

18 questions from 2017–2026, asked in 10 of 10 papers, about 1.7 a paper. Electromagnetic Waves alone had 18.

Chapter analysisStudy this chapterPractise this chapter

Electromagnetic Waves: questions per paper

0241’171’182’192’202’212’222’232’242’252’26