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Saturday, 31 October

JEE Main 2021 · PhysicsMultiple choiceSingle correctMediumConceptual

JEE Main 25 February 2021, Shift 2, Physics Q1

Question 1 of 90 in this shift, Physics question 1 of 30, Section A.

If e is the electronic charge, c is the speed of light in free space and h is Planck’s constant, the quantity 14πε0∣e∣2ℏc\frac{1}{4\pi\varepsilon_0}\frac{|e|^2}{\hbar c} has dimensions of :
  1. (1)[M L T0][\mathrm{M\,L\,T^0}]
  2. (2)[M L T−1][\mathrm{M\,L\,T^{-1}}]
  3. (3)[M0 L0 T0][\mathrm{M^0\,L^0\,T^0}]Official answer
  4. (4)[L C−1][\mathrm{L\,C^{-1}}]

Official answer

Option 3

NTA final key.

Chapter
Units and Measurements
Topic
No close match in our taxonomy
Idea tested
No close match in our taxonomy

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.