Two protons are projected simultaneously from a fixed point with the same velocity v into a region, magnetic there exists a uniform magnetic field. The magnetic field strength at B and it si perpendicular to the initial direction of v. One proton starts at time t=0 and another proton at `t = (pim)/(2qB)`. The separation between them at time `t = (pim)/(qB)` (where, m and q are the mass and charge of proton), will be approximately