JEE Main 2021 · PhysicsMultiple choiceSingle correctEasyCalculation

JEE Main 4 August 2021, Shift 1, Physics Q19

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

The moment of force

\overline{F}=2\hat{i}+\hat{j}+2\hat{k}

acting at a point

-\hat{i}+2\hat{j}+\hat{k}

about the point

3\hat{i}+\hat{j}+4\hat{k}

is given by

(1) $10\hat{i}+4\hat{j}-12\hat{k}$
(2) $10\hat{i}-4\hat{j}+12\hat{k}$
(3) $5\hat{i}+2\hat{j}-6\hat{k}$ Official answer
(4) $5\hat{i}-2\hat{j}+6\hat{k}$

Official answer

Option 3

NTA final key.

Chapter: System of Particles and Rotational Motion
Topic: Torque and Equilibrium
Idea tested: Torque Calculation

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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.