A) 1
B) 2
C) 3
D) 4
E) 5
Correct Answer: B
Solution :
The scalar product of two vectors is \[\overrightarrow{A}.\overrightarrow{B}=AB\cos \theta \] When \[\theta =90{}^\circ ,\]then \[\cos 90{}^\circ =0\] \[\overrightarrow{A}.\overrightarrow{B}=0\] \[(2\hat{i}+3\hat{j}+4\hat{k}).(\hat{i}+2\hat{j}-n\hat{k})=0\] \[\Rightarrow \] \[2+6-4n=0\] \[\Rightarrow \] \[n=\frac{8}{4}=2\]You need to login to perform this action.
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