MCQ
A vector is represented by $3 \hat{i}+\hat{j}+2 \hat{k}$. Its length in $X Y$ plane is
- A2
- B$\sqrt{14}$
- ✓$\sqrt{10}$
- D$\sqrt{5}$
✓
Answer
Correct option: C.
$\sqrt{10}$
(c)$\begin{aligned}& \vec{R}=3 \hat{i}+\hat{j}+2 \hat{k} \\& \therefore \text { Length in } X Y \text { plane }=\sqrt{R_x^2+R_y^2}=\sqrt{3^2+1^2}=\sqrt{10}\end{aligned}$
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