question_answer

If the position vectors of A and B are \[\mathbf{i}+3\mathbf{j}-7\mathbf{k}\] and \[5\mathbf{i}-2\mathbf{j}+4\mathbf{k},\] then the direction cosine of \[\overrightarrow{AB}\] along y-axis is                                                                                                  [MNR 1989]

A) \[\frac{4}{\sqrt{162}}\]       

B) \[-\frac{5}{\sqrt{162}}\]

C) 5             

D) 11