Q 12-04-039JEE MainJEE Main 2026 (5 Apr, Shift 1)Medium
The charged particle moving in a uniform magnetic field of $(3\hat{i} + 2\hat{j})$ T has an acceleration $\left(4\hat{i} - \dfrac{x}{2}\hat{j}\right)\ \text{m/s}^2$. The value of $x$ is
Numerical value type. Enter your answer.
Answer: 12
Concept. The magnetic force (and hence the acceleration) is always perpendicular to $\vec B$: $\vec a\cdot\vec B=0$.
Step 1. Dot product. $4\times3-\dfrac x2\times2=0$.
Answer. $x=12$.
Solution by Sreeraj P, M.Sc Physics
