Question

If $\vec { A } \times \vec { B } = \vec { C }$then which of the following statements is wrong

• A. $\vec { C } \perp \vec { A }$
• B. $\vec { C } \perp \vec { B }$
• C. $\vec { C } \perp ( \vec { A } + \vec { B } )$
• D. $\vec { C } \perp ( \vec { A } \times \vec { B } )$

Answer 1

Answer: (D)

$\vec { C } \perp ( \vec { A } \times \vec { B } )$

Answer 2

From the property of vector product, we notice that $( \vec { A } \times \vec { B } )$ gives a vector $\vec { C }$ which can not be perpendicular to itself. Thus the last statement is wrong.