Question

If the three vectors A,B and C satisfy the relation $A.B=0$ and $A.C=0,$ then vector A is parallel to

• A. A
• B. B
• C. $A\times B$
• D. $~B\times C$

Answer 1

Answer: (D)

Given. $A.B=0,\,$
$\therefore$ A is $\bot$ to B also $A.C=0,$
$\therefore$ A is $\bot$ to C
As $B\times C$ is $\bot$ to both B and C,
so $B\times C$ is parallel to A.