MCQ
$\vec A$ and $\vec B$ are two vectors and $\theta$ is the angle between them, if $|\vec A \times \vec B|=\sqrt 3(\vec A \cdot \vec B) $ the value of $\theta$ is ......... $^o$
- ✓$60$
- B$45$
- C$180$
- D$0$
✓
Answer
Correct option: A.
$60$
a
$\left| {\vec A \times \vec B} \right| = \sqrt 3 \left( {\vec A \cdot \vec B} \right)$
$\left| {\vec A \times \vec B} \right| = \sqrt 3 \left( {\vec A \cdot \vec B} \right)$
$AB\sin \theta = \sqrt 3 AB\cos \theta$
$\tan \theta = \sqrt 3$
$\theta = {\tan ^{ - 1}}\sqrt 3 = {60^ \circ }$
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