Q 12-04-090JEE MainJEE Main 2024 (29 Jan, Shift 2)Easy
A charge of $4.0\ \mu\text{C}$ is moving with a velocity of $4.0\times10^6\ \text{m s}^{-1}$ along the positive $y$-axis under a magnetic field $\vec B$ of strength $(2\hat k)\ \text{T}$. The force acting on the charge is $x\hat i\ \text{N}$. The value of $x$ is ______.
Numerical value type. Enter your answer.
Answer: 32
$$\vec F = q\vec v\times\vec B = 4\times10^{-6}\times4\times10^6\,(\hat j\times2\hat k) = 16\times2\,\hat i = 32\,\hat i\ \text{N}$$
So $x = 32$.
Solution by Sreeraj P, M.Sc Physics