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