Learn

Saturday, 31 October

JEE Main 2021 · PhysicsMultiple choiceOtherEasyConceptual

JEE Main 31 August 2021, Shift 2, Physics Q20

Question 20 of 90 in this shift, Physics question 20 of 30, Section A.

Choose the incorrect statement : (a) The electric lines of force entering into a Gaussian surface provide negative flux. (b) A charge 'q' is placed at the centre of a cube. The flux through all the faces will be the same. (c) In a uniform electric field net flux through a closed Gaussian surface containing no net charge, is zero. (d) When electric field is parallel to a Gaussian surface, it provides a finite non-zero flux. Choose the most appropriate answer from the options given below :
  1. (1)(a) and (c) Only
  2. (2)(b) and (d) Only
  3. (3)(c) and (d) Only
  4. (4)(d) OnlyOfficial answer

Official answer

Option 4

NTA final key.

Chapter
Electric Charges and Fields
Topic
Gauss's Law
Idea tested
Electric Flux Calculation

Same idea in other shifts

Asked 6× in all
  1. 7 Apr 2025, Shift 2 · Q50The electric field in a region is given by E⃗=(2i^+4j^+6k^)×103\vec{E}=\left(2\hat{i}+4\hat{j}+6\hat{k}\right)\times10^3 N/C. The flux of the field through…EasyNumerical value
  2. 8 Apr 2024, Shift 1 · Q55An electric field, E⃗=2i^+6j^+8k^6\vec{E}=\frac{2\hat{i}+6\hat{j}+8\hat{k}}{\sqrt{6}} passes through the surface of 4 m2^2 area having unit vector…EasyNumerical value
  3. 25 Feb 2021, Shift 1 · Q26The electric field in a region is given by E⃗=(35E0i^+45E0j^)NC\vec{E}=\left(\frac{3}{5}E_0\hat{i}+\frac{4}{5}E_0\hat{j}\right)\frac{N}{C}. The ratio of…EasyNumerical value
  4. 17 Mar 2021, Shift 2 · Q26The electric field in a region is given by E⃗=25E0i^+35E0j^\vec{\mathrm{E}}=\frac{2}{5}\mathrm{E_0}\hat{i}+\frac{3}{5}\mathrm{E_0}\hat{j} with…EasyNumerical value
  5. 9 Jan 2020, Shift 2 · Q22An electric field E⃗=4x i^−(y2+1) j^\vec{E} = 4x\,\hat{i} - (y^2+1)\,\hat{j} N/C passes through the box shown in figure. The flux of the electric field…MediumNumerical valueHas 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.