JEE Main 2021 · PhysicsNumerical answerNumerical valueEasyCalculation

JEE Main 24 February 2021, Shift 1, Physics Q22

Question 22 of 90 in this shift, Physics question 22 of 30, Section B.

An unpolarized light beam is incident on the polarizer of a polarization experiment and the intensity of light beam emerging from the analyzer is measured as 100 Lumens. Now, if the analyzer is rotated around the horizontal axis (direction of light) by

30^\circ

in clockwise direction, the intensity of emerging light will be __________ Lumens.

Official answer

NTA final key.

Chapter: Wave Optics
Topic: Polarization
Idea tested: Malus's Law Calculation

Same idea in other shifts

Asked 7× in all

4 Apr 2026, Shift 2 · Q42An unpolarized light of certain intensity passes through a combination of two polarizers whose transmission axes are at $30^\circ$ and…MediumSingle correct
6 Apr 2026, Shift 1 · Q47An unpolarized light of intensity $I_0$ passes through polarizer and then through a certain optically active solution and finally it goes…MediumNumerical value
30 Jan 2024, Shift 2 · Q45A beam of unpolarised light of intensity $I_o$ is passed through a polaroid $A$ and then through another polaroid $B$ which is oriented so…EasySingle correct
10 Apr 2023, Shift 1 · Q57Unpolarised light of intensity $32\,Wm^{-2}$ passes through the combination of three polaroids such that the pass axis of the last…MediumNumerical value
29 Jul 2022, Shift 2 · Q39An unpolarised light beam of intensity $2I_0$ is passed through a polaroid P and then through another polaroid Q which is oriented in such…EasySingle correct
30 Jul 2022, Shift 2 · Q14Two poloroids P $_1$ and P $_2$ are placed parallel to each other with common axis.The light of intensity I $_0$ passes through a polaroid…EasySingle correct

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. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.