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Saturday, 31 October

JEE Main 2026 · PhysicsMultiple choiceDiagram basedHardConceptual

JEE Main 4 April 2026, Shift 1, Physics Q45

Question 45 of 75 in this shift, Physics question 20 of 25, Section A.

An unpolarized light is incident on the plane interface of air-dielectric medium shown in figure. If the incident angle is equal to Brewster angle, identify the expression representing reflected wave.

The figure, in words

Light rays incident obliquely from air onto the top face of a dielectric medium block; axes: x along the surface (in the plane of incidence direction, drawn going up-right), y along the surface to the right, z pointing downward into the medium.
  1. (1)(Exi^+Eyj^)sin⁡(kx−kz−ωt)(E_x\hat{i}+E_y\hat{j})\sin(kx-kz-\omega t)Official answer
  2. (2)(Exi^+Ezk^)sin⁡(kx+ky−ωt)(E_x\hat{i}+E_z\hat{k})\sin(kx+ky-\omega t)
  3. (3)(Exj^+Eyk^)sin⁡(ky+kz−ωt)(E_x\hat{j}+E_y\hat{k})\sin(ky+kz-\omega t)
  4. (4)(Exi^+Eyj^+Ezk^)sin⁡(kx+ky−kz−ωt)(E_x\hat{i}+E_y\hat{j}+E_z\hat{k})\sin(kx+ky-kz-\omega t)

Official answer

Option 1

NTA final key.

Chapter
Wave Optics
Topic
Polarization
Idea tested
Polarization by Reflection

Same topic in other shifts

All Polarization questions
  1. 4 Apr 2026, Shift 2 · Q42An unpolarized light of certain intensity passes through a combination of two polarizers whose transmission axes are at 30∘30^\circ and…MediumSingle correct
  2. 6 Apr 2026, Shift 1 · Q47An unpolarized light of intensity I0I_0 passes through polarizer and then through a certain optically active solution and finally it goes…MediumNumerical value
  3. 4 Apr 2025, Shift 2 · Q40Two polarisers P1P_1 and P2P_2 are placed in such a way that the intensity of the transmitted light will be zero. A third polariser P3P_3…MediumSingle correct
  4. 30 Jan 2024, Shift 2 · Q45A beam of unpolarised light of intensity IoI_o is passed through a polaroid AA and then through another polaroid BB which is oriented so…EasySingle correct
  5. 31 Jan 2024, Shift 2 · Q45When unpolarized light is incident at an angle of 60∘60^\circ on a transparent medium from air, the reflected ray is completely polarized.…EasySingle correct
  6. 10 Apr 2023, Shift 1 · Q57Unpolarised light of intensity 32 Wm−232\,Wm^{-2} passes through the combination of three polaroids such that the pass axis of the last…MediumNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.