# Does magnetic field make particle move in the direction of magnetic field(In circles)?

A particle with mass $$m$$ moves freely through space and there is no electromagnetic field. At moment $$t = 0$$ a uniform magnetic field is turned on with field strength $$B$$, and direction perpendicular to the velocity of the particle. At moment $$t = T$$ the field is turned off. What is the deviation of the direction of the particle that happened while uniform field was turned on?
To solve this I must assume that the magnetic force changes the particle's direction, not magnitude. So I will get $$F_{cp}$$ (centripetal force) $$= F_{mg}$$ (force of the magnetic field).