A proton moves in the –x-direction and encounters a uniform magnetic field pointing in the +x-direction. In what direction is the resulting magnetic force on the proton? (a) The proton experiences no magnetic force.
(b) +x-direction
(c) −y-direction
(d) +y-direction

Video Transcript

This is College Physics Answers with Shaun Dychko. Because this proton's velocity is parallel to the magnetic field or anti-parallel if you want to be precise because they're going in opposite directions, there is no magnetic force at all on this moving charge.