Question

If vectors $\overrightarrow { \boldsymbol { A } }$ and $\vec { B }$ are perpendicular to each other, then which of the following statements is valid?

• A. $\overrightarrow { \boldsymbol { A } }$ × $\vec { B }$ = $\overrightarrow { \boldsymbol { A } }$ . $\vec { B }$
• B. $\overrightarrow { \boldsymbol { A } }$ × $\vec { B }$ = 0
• C. $\overrightarrow { \boldsymbol { A } }$ . $\vec { B }$ = 0
• D. $\overrightarrow { \boldsymbol { A } }$ . $\vec { B }$ = | $\overrightarrow { \boldsymbol { A } }$ | | $\vec { B }$ |

Answer 1

Answer: (C)

$\overrightarrow { \boldsymbol { A } }$ . $\vec { B }$ = 0

Answer 2

$\overrightarrow { \mathrm { A } }$ ⊥ $\vec { B }$ . Then.

$\overrightarrow { \mathrm { A } }$ . $\vec { B }$ = |A||B|cos90⁰ = 0

Hence (3) is correct.