Question

The inner (dot) product of two vectors $\overrightarrow{P}$ and $\overrightarrow{Q}$ is zero. The angle (degree) between the two vectors is

• A. zero
• B. 30
• C. 90
• D. 120

Answer 1

The correct option is C 90

$\overrightarrow{P}.\overrightarrow{Q}=0$
$\Rightarrow \left|\overrightarrow{P}\right|\left|\overrightarrow{Q}\right|cos\theta$ = 0
$\Rightarrow$ cos$\theta =0$
$\Rightarrow$ $\theta$ = ${90}^{\circ }$