Direction of Magnetic Force
Whenever a charged particle with charge q and velocity enters a region with field it experiences a force given by
The direction of the force is given by the right hand thumb rule or the curl rule
There is a second right hand rule that shows the direction of the force on a positive charge in a magnetic field. Point your index finger along the direction of the particle's velocity. If your middle finger points along the magnetic field, your thumb will point in the direction of the force. NOTE: For negative charge reverse the direction of the force (or use your left hand).