# 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).
As you mentioned, the force experienced by a moving charged particle in a magnetic field is perpendicular to both the magnetic field and the particle's velocity. This force causes the direction of the velocity of the particle to change, so the direction of the force in the next moment also changes. When you draw this out, the force always towards a point in the circle. 