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Vector — JEE physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceJEE physicsVector1 Mark
MCQ
If two vectors $2 \hat{i}+3 \hat{j}-\hat{k}$ and $-4 \hat{i}-6 \hat{j}-\lambda \hat{k}$ are parallel to each other then value of $\lambda$ be
  • A
    2
  • ✓
    3
  • C
    4
✓

Answer

Correct option: B.
3
(b) Let $\vec{A}=2 \hat{i}+3 \hat{j}-\hat{k}$ and $\vec{B}=-4 \hat{i}-6 \hat{j}+\lambda \hat{k}$ $\vec{A}$ and $\vec{B}$ are parallel to each other$\frac{a_1}{b_1}=\frac{a_2}{b_2}=\frac{a_3}{b_3} \text { i.e. } \frac{2}{-4=\frac{3}{-6}=\frac{-1}{\lambda} \Rightarrow \lambda=2 .$

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