Q 11-03-021NEETJEE MainEasy
The magnitude of the component of $\vec{A} = 3\hat{i} + 4\hat{j}$ along the direction of $\vec{B} = \hat{i} + \hat{j}$ is
Answer: (B) $\dfrac{7}{\sqrt{2}}$
Concept. Component of $\vec A$ along $\vec B$: $\vec A \cdot \hat B = \dfrac{\vec A \cdot \vec B}{|\vec B|}$.
Step 1. Substitute. $\dfrac{3 + 4}{\sqrt2} = \dfrac{7}{\sqrt2}$.
Answer. $\dfrac{7}{\sqrt2}$ (Option B).
Solution by Sreeraj P, M.Sc Physics