Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Vectors

Question:

Match List-I with List-II

List-I

List-II

(A) If vector $\vec a$ and $\vec b$ are such that $\vec a = λ\vec b$ and $|\vec a| = |\vec b|$, then

(I) $\vec a$ and $\vec b$ are orthogonal

(B) Projection vector of $\vec a$ on $\vec b$

(II) $[0, 12]$

(C) $\vec a$ and $\vec b$ are non-zero vectors such that $|\vec a+\vec b|=|\vec a-\vec b|$ then

(III) $\vec a = ±\vec b$

(D) If $|\vec a| = 4,-3 ≤λ≤ 2$, then the range of $|λ\vec a|$

(IV) $\left(\frac{\vec a.\vec b}{|\vec b|^2}\right)\vec b$

Choose the correct answer from the options given below:

Options:

(A)-(III), (B)-(IV), (C)-(II), (D)-(I)

(A)-(I), (B)-(III), (C)-(IV), (D)-(II)

(A)-(III), (B)-(IV), (C)-(I), (D)-(II)

(A)-(I), (B)-(III), (C)-(II), (D)-(IV)

Correct Answer:

(A)-(III), (B)-(IV), (C)-(I), (D)-(II)

Explanation:

The correct answer is Option (3) → (A)-(III), (B)-(IV), (C)-(I), (D)-(II)

(A) If $\vec{a} = \lambda \vec{b}$ and $|\vec{a}| = |\vec{b}|$

$\Rightarrow |\lambda| = 1 \Rightarrow \lambda = \pm 1 \Rightarrow \vec{a} = \pm \vec{b}$

⟹ (A) → (III)

(B) Projection vector of $\vec{a}$ on $\vec{b}$ is $\left(\frac{\vec{a} \cdot \vec{b}}{|\vec{b}|^2}\right)\vec{b}$

⟹ (B) → (IV)

(C) $|\vec{a} + \vec{b}| = |\vec{a} - \vec{b}| \Rightarrow \vec{a} \cdot \vec{b} = 0$

⟹ $\vec{a}$ and $\vec{b}$ are orthogonal

⟹ (C) → (I)

(D) $|\lambda \vec{a}| = |\lambda||\vec{a}| = 4|\lambda|$, where $\lambda \in [-3, 2]$

⟹ $|\lambda| \in [0, 3] \Rightarrow |\lambda \vec{a}| \in [0, 12]$

⟹ (D) → (II)