Kinematics Question 253

Question: If two vectors $ 2\hat{i}+3\hat{j}-\hat{k} $ and $ -4\hat{i}-6\hat{j}-\lambda \hat{k} $ are parallel to each other then value of l be

Options:

A) 0

B) 2

C) 3

D) 4

Show Answer

Answer:

Correct Answer: B

Solution:

Let $ \overrightarrow{A}=2\hat{i}+3\hat{j}-\hat{k} $ and $ \overrightarrow{B}=-4\hat{i}-6\hat{j}+\lambda \hat{k} $

$ \overrightarrow{A} $ and $ \overrightarrow{B} $ are parallel to each other $ \frac{a_1}{b_1}=\frac{a_2}{b_2}=\frac{a_3}{b_3} $ i.e. $ \frac{2}{-4}=\frac{3}{-6}=\frac{-1}{\lambda } $
$ \Rightarrow \lambda =2 $ .



NCERT Chapter Video Solution

Dual Pane