If an electron and a proton having same momenta enter perpendicular to a magnetic field, then

  1. they will move undeflected
  2. curved path of electron and proton will be same (ignoring the sense of revolution)
  3. path of proton is more curved
  4. curved path of electron is more curved than that of the proton


Radius of a circular path in a magnetic field depends on the momentum and in this question both have same momentum.

Therefore, they would have same curved path.

The correct option is B.