An `alpha` particle (mass = 4amu) and a singly charged sulfur ion (mass 32 amu) are initially at rest. They are accelerated through potential V and then allowed to pass into a region of uniform magnetic field which is normal to velocities of the particles. Within this region the `alpha` particle and the sulfur ion move in circular orbits of radii `r_a` and `r_s` resp. The ratio `(r_s/r_a)` is