Question

If the two vectors $\overline{A}=2\hat{i}+3\hat{j}+4\hat{}and\overline{B}=\hat{i}+2\hat{j}-n\hat{k}$ are perpendicular, then the value of n is:

• A. 1
• B. 2
• C. 3
• D. 5

Answer 1

The correct option is B

2

Two, vectors are said to be perpendicular when their dot product is zero.

$\overline{A}\overline{B}=0$

$(2\widehat{+}3\hat{j}+4\widehat{)}(\hat{i}+2\hat{j}-n\hat{k})=0$

$2+6-4n=0$

$n=2$