Question

The ratio of maximum and minimum magnitudes of the resultant of two vectors $\overrightarrow{a}$ and $\overrightarrow{b}$ is 3 : 1. Now , $|\overrightarrow{a}|$ is equal to :

• A. $|\overrightarrow{b}|$
• B. $2|\overrightarrow{b}|$
• C. $3|\overrightarrow{b}|$
• D. $4|\overrightarrow{b}|$

Answer 1

The correct option is B $2|\overrightarrow{b}|$

$\frac{|\overrightarrow{a}|+|\overrightarrow{b}|}{|\overrightarrow{a}|-|\overrightarrow{b}|}=\frac{3}{1}$
$|\overrightarrow{a}|+|\overrightarrow{b}|=3|\overrightarrow{a}|-3|\overrightarrow{b}|$
$2|\overrightarrow{a}|=4|\overrightarrow{b}|$
$|\overrightarrow{a}|=2|\overrightarrow{b}|$