Bainbridge's mass spectrometer separates ion having the same velocity. The ions, after enteering through slits, `S_(1)` and `S_(2)`, pass through a velocity selector composed of an electric field pproduced by the charged plates P and P' abd a magnetic field `vecB` perpendicular to electric field and the ion path.Thew ions that then passs undeviated through the crossed `vecE`1 and `vecB` fields enter into a region where a second magnetic field `vecB` exists, where they are made to follow circular path. A photographic plate ( or a modern detector) registors their arrival. If r is the radius of the circular orbit , then specific charge `(q)/(m)` of ion is

Options

A. `(E)/(rBB')`
B. `(2E)/(rBB')`
C. `(3E)/(2rBB')`
D. `(2E)/(3rBB')`

Answer

A