A positive charge ‘q’ of mass ‘m’ is moving along the +x axis. We wish to apply a uniform magnetic field B for timet so that the charge reverses its direction crossing the y axis at a distance d. Then :
As we discussed in concept
Time period of charged particle -
- wherein
independent of speed of particle
and
Radius of charged particle -
-
The applied magnetic field provides the required centripetal force to the charge particle so that it can move in circular path of radius d/2