Question

$\overrightarrow{A}$ is a vector quantity such that $|\overrightarrow{A}|=$ non-zero constant. Which of the following expressions is true for $\overrightarrow{A}$ ?

• A. $\overrightarrow{A}\cdot \overrightarrow{A}=0$
• B. $\overrightarrow{A}\times \overrightarrow{A}<0$
• C. $\overrightarrow{A}\times \overrightarrow{A}=0$
• D. $\overrightarrow{A}\times \overrightarrow{A}>0$

Answer 1

Answer: (C)

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