JEE Main 2024 · MathsMultiple choiceSingle correctEasyApplication

JEE Main 30 January 2024, Shift 2, Maths Q18

Question 18 of 90 in this shift, Maths question 18 of 30, Section A.

Let

\vec{a}

and

\vec{b}

be two vectors such that

|\vec{b}| = 1

and

|\vec{b} \times \vec{a}| = 2

. Then

\left|(\vec{b} \times \vec{a}) - \vec{b}\right|^2

is equal to

(1) $1$
(2) $3$
(3) $4$
(4) $5$ Official answer

Official answer

Option 4

NTA final key.

Chapter: Vector Algebra
Topic: Dot Product
Idea tested: Expansion of Sum of Vectors Squared

Same idea in other shifts

Asked 3× in all

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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 42 of the 174 JEE Main shifts held from 2017 to 2026.