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Saturday, 31 October

JEE Main 2021 · PhysicsMultiple choiceSingle correctMediumCalculation

JEE Main 16 March 2021, Shift 2, Physics Q19

Question 19 of 90 in this shift, Physics question 19 of 30, Section A.

Find out the surface charge density at the intersection of point x=3x=3 m plane and xx-axis, in the region of uniform line charge of 8 nC/m lying along the zz-axis in free space.
  1. (1)47.88 C/m
  2. (2)0.07 nC m−20.07\ \mathrm{nC\,m^{-2}}
  3. (3)0.424 nC m−20.424\ \mathrm{nC\,m^{-2}}Official answer
  4. (4)4.0 nC m−24.0\ \mathrm{nC\,m^{-2}}

Official answer

Option 3

NTA final key.

Chapter
Electric Charges and Fields
Topic
Electric Field
Idea tested
Finite/Infinite Line Field

Same idea in other shifts

Asked 2× in all
  1. 26 Feb 2021, Shift 1 · Q12Find the electric field at point P (as shown in figure) on the perpendicular bisector of a uniformly charged thin wire of length L…MediumDiagram basedHas a figure

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.