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Saturday, 31 October

JEE Main 2021 · PhysicsMultiple choiceDiagram basedEasyApplication

JEE Main 25 February 2021, Shift 1, Physics Q5

Question 5 of 90 in this shift, Physics question 5 of 30, Section A.

In an octagon ABCDEFGH of equal side, what is the sum of AB→+AC→+AD→+AE→+AF→+AG→+AH→\overrightarrow{AB}+\overrightarrow{AC}+\overrightarrow{AD}+\overrightarrow{AE}+\overrightarrow{AF}+\overrightarrow{AG}+\overrightarrow{AH}, if, AO→=2i^+3j^−4k^\overrightarrow{AO}=2\hat{i}+3\hat{j}-4\hat{k}

The figure, in words

A regular octagon with vertices labelled A, B, C, D, E, F, G, H; A and B are at the top edge, C and D on the right side, E and F at the bottom edge, G and H on the left side. A dot labelled O is drawn inside near the centre.
  1. (1)16i^+24j^+32k^16\hat{i}+24\hat{j}+32\hat{k}
  2. (2)−16i^−24j^+32k^-16\hat{i}-24\hat{j}+32\hat{k}
  3. (3)16i^−24j^+32k^16\hat{i}-24\hat{j}+32\hat{k}
  4. (4)16i^+24j^−32k^16\hat{i}+24\hat{j}-32\hat{k}Official answer

Official answer

Option 4

NTA final key.

Chapter
Motion in a Plane
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. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.