A charged particle having a mass of $1.6\times 10^{–26}\mathrm{ }\mathrm{k}\mathrm{g}$ comes out of accelerator tube with kinetic energy $2\times 10^3\mathrm{ }\mathrm{e}\mathrm{V}$. Calculate the smallest magnitude of the magnetic field that should be applied in vertically downwards direction to just prevent the charged particle from colliding the plate (Assume charge on particle = charge of the proton)