Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Vectors

Question:

Let $\vec{a}=4 \hat{i}-\hat{j}+3 \hat{k}$ and $\vec{b}=-2 \hat{i}+\hat{j}-2 \hat{k}$. Then

(A) $\vec{a}$ is a unit vector
(B) $\vec{a} \times \vec{b}=-\hat{i}+2 \hat{j}+2 \hat{k}$
(C) $\vec{a}$ and $\vec{b}$ are parallel vectors
(D) $\vec{a}$ and $\vec{b}$ are neither parallel nor perpendicular vectors

Choose the correct answer from the options given below:

Options:

(B) and (C) Only

(C) and (D) Only

(D) Only

(B) and (D) Only

Correct Answer:

(B) and (D) Only

Explanation:

The correct answer is Option (4) - (B) and (D) Only

$|\vec a|=\sqrt{4^2+(-1)^2+3^2}=\sqrt{26}$ (A) false (Not unit vector)

$\vec a×\vec b|=-\hat i+2\hat j+2\hat k$ ((B) true)

(C) false as $\vec a×\vec b!=\vec 0$

(D) True as $\vec a×\vec b!=\vec 0$