MCQ
Two vectors $\vec{a}=a_1 \hat{i}+a_2 \hat{j}+a_3 \hat{k}$ and $\vec{b}=b_1 \hat{i}+b_2 \hat{j}+b_3 \hat{k}$ are collinear if
  • A
    $a_1 b_1+a_2 b_2+a_3 b_3=0$
  • B
    $\frac{a_1}{b_1}=\frac{a_2}{b_2}=\frac{a_3}{b_3}$
  • $a_1=b_1, a_2=b_2, a_3=b_3$
  • D
    $a_1+a_2+a_3=b_1+b_2+b_3$

Answer

Correct option: C.
$a_1=b_1, a_2=b_2, a_3=b_3$
$a_1=b_1, a_2=b_2, a_3=b_3$

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