Question

For a non-zero vector $\overrightarrow{a}$, which of the following statement is true

• A. $\overrightarrow{a}.\overrightarrow{a}\geq0$
• B. $\overrightarrow{a}.\overrightarrow{a}>\,0$
• C. $\overrightarrow{a}.\overrightarrow{a}=\,0$
• D. $\overrightarrow{a}.\overrightarrow{a}\leq\,0$

Answer 1

Answer: (B)

$\overrightarrow{a}.\overrightarrow{a}>\,0$

Answer 2

$\vec{a}\cdot\vec{b}=\left|\vec{a}\right|^2 > 0\quad\left[\because \vec{a} \ne 0\right]$