MCQ
The component of vector $A=2 \hat{i}+3 \hat{j}$ along the vector $\hat{i}+\hat{j}$ is
  • $\frac{5}{\sqrt{2}}$
  • B
    $10 \sqrt{2}$
  • C
    $5 \sqrt{2}$
  • D
    5

Answer

Correct option: A.
$\frac{5}{\sqrt{2}}$
(a) $\frac{\vec{A} \cdot \vec{B}}{|\vec{i}+\vec{j}|}=\frac{(2 \hat{i}+3 \hat{j})(\hat{i}+\hat{j})}{\sqrt{2}}=\frac{2+3}{\sqrt{2}}=\frac{5}{\sqrt{2}}$

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