question_answer

If \[\mathbf{a}=\mathbf{i}-2\mathbf{j}+3\mathbf{k}\] and \[\mathbf{b}=3\mathbf{i}+\mathbf{j}+2\mathbf{k},\] then the unit vector perpendicular to a and b is [MP PET 1996]

A)             \[\frac{\mathbf{i}+\mathbf{j}+\mathbf{k}}{\sqrt{3}}\]

B)             \[\frac{\mathbf{i}-\mathbf{j}+\mathbf{k}}{\sqrt{3}}\]

C)             \[\frac{-\mathbf{i}+\mathbf{j}+\mathbf{k}}{\sqrt{3}}\]

D)             \[\frac{\mathbf{i}-\mathbf{j}-\mathbf{k}}{\sqrt{3}}\]