MCQ
$\vec{A}$ is a vector quantity such that $|\vec{A}|=$ nonzero constant. Which of the following expressions is true for $\vec{A}$ $?$
  • A
    $\overrightarrow{ A }\cdot \overrightarrow{ A }=0$
  • B
    $\overrightarrow{ A } \times \overrightarrow{ A }<0$
  • $\overrightarrow{ A } \times \overrightarrow{ A }=0$
  • D
    $\overrightarrow{ A } \times \overrightarrow{ A }>0$

Answer

Correct option: C.
$\overrightarrow{ A } \times \overrightarrow{ A }=0$
c
$|\overrightarrow{ A }| \neq 0$

$\overrightarrow{ A } \times \overrightarrow{ A }=|\overrightarrow{ A }||\overrightarrow{ A }| \sin 0^{\circ} \hat{ n }=0$

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