Question

A proton is moving along Z-axis in a magnetic field. The magnetic field is along X-axis. The proton will experience a force along which axis?

Answer 1

$\text{Lorent's Force is given by}\\\vec{F}=q\vec{v}\times\vec{B}\\\text{Therefore for a proton,}\\\hat{F}=+\hat{v}\times\hat{B}=\hat{k}\times\hat{i}=\hat{j}\rightarrow\text{Y-Axis}\\\text{Alternatively you may use Fleming's Left Hand rule}\\\text{and align your hand as shown in figure, you will get the same answer.}$