Question

what determines the direction of magnetic force? what determines the direction of magnetic force? @Physics

Answer 1

The force of a magnetic field on a moving charge is given by the Lorentz Force. \[\vec F = q\vec v \times \vec B\]If you know what a cross product is, the direction should be well and familiar to you. If you are not familiar with this, then you should learn one of the numerous variations on the right-hand-rule that will tell you the direction of a vector that results from a cross product. A simple one is as follows: First align the thumb of your right hand along the direction of the velocity vector (first vector in the cross product). Then extend out your other four fingers perpendicularly and align those up with the direction of the magnetic field. Once you have done both of these, the force vector will be pointing perpendicularly out of your palm. The force always perpendicular to both the velocity and magnetic field vectors. It's important that you do the vectors in the right order as the cross product is not commutative. Let me know if you need any more help and I will try my best.