MCQ
If $\overrightarrow A \times \overrightarrow B=\overrightarrow B \times \overrightarrow A$ then the angle between $\overrightarrow A$ and $\overrightarrow B$ is
  • A
    $\pi / 2$
  • B
    $\pi / 3$
  • $\pi$
  • D
    $\pi / 4$

Answer

Correct option: C.
$\pi$
c
(c) We know that $\overrightarrow A \times \overrightarrow B = - (\overrightarrow B \times \overrightarrow A )$ because the angle between these two is always $90^°$.

But if the angle between $\overrightarrow A $ and $\overrightarrow B $ is $0^°$. Then $\overrightarrow A \times \overrightarrow B = \overrightarrow B \times \overrightarrow A = 0$.

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