Question

If $\vec{P}\cdot \vec{Q}=PQ$, then angle between $\vec{P}$ and $\vec{Q}$ is

• A. $0^{\circ }$
• B. $30^{\circ }$
• C. $45^{\circ }$
• D. $60^{\circ }$

Answer 1

Answer: (A)

$\cos \theta =\frac{\vec{P}\cdot \vec{Q}}{PQ}=1$
$\therefore \theta =0^{\circ }$