JEE Main 2021 · PhysicsMultiple choiceDiagram basedMediumMulti-step

JEE Main 26 August 2021, Shift 2, Physics Q7

Question 7 of 90 in this shift, Physics question 7 of 30, Section A.

The angle between vector

\left(\vec{A}\right)

and

\left(\vec{A}-\vec{B}\right)

is :

The figure, in words

Vector diagram: vector A drawn from a left point O to a point P; vector B drawn from P up to the upper right (arrow at top right); a solid line from O to the top right end (arrowhead there, unlabelled); the angle between A and B at P is marked 120 degrees; from P a dashed line labelled -B goes down to a lower point, and a solid arrow from O to that lower point; angle beta is marked at O between A and the lower solid line.

(1) $\tan^{-1}\left(\frac{A}{0.7\,B}\right)$
(2) $\tan^{-1}\left(\frac{\sqrt{3}\,B}{2A-B}\right)$ Official answer
(3) $\tan^{-1}\left(\frac{B\cos\theta}{A-B\sin\theta}\right)$
(4) $\tan^{-1}\left(\frac{-\frac{B}{2}}{A-B\frac{\sqrt{3}}{2}}\right)$

Official answer

Option 2

NTA final key.

Chapter: Motion in a Plane
Topic: No close match in our taxonomy
Idea tested: No close match in our taxonomy