If a charged particle at rest experiences no electro - magnetic force

Case – I

$$\begin{gathered} If E=0 and B=0,Then the charged particle will be at rest. \\ Case-II \\ If E=0 and B\ne 0 and \theta =0^0 \left(or\right){180}^0 \\ {F}_m=0\left[The charged particle,it will on the magnetic lines of force\right] \\ Now also it will be at rest \end{gathered}$$