Q 11-03-089JEE MainJEE Main 2023 (24 Jan, Shift 2)Easy
If two vectors $\vec P=\hat i+2m\hat j+m\hat k$ and $\vec Q=4\hat i-2\hat j+m\hat k$ are perpendicular to each other, then the value of $m$ will be
Answer: (B) 2
$\vec P\cdot\vec Q=4-4m+m^2=0\Rightarrow(m-2)^2=0\Rightarrow m=2$.
Solution by Sreeraj P, M.Sc Physics