Consider current flowing down a large, thick wire from left to right. In the conventional current model, a current is made up of positive charges moving with a velocity in the same direction as current. The current is exposed to a magnetic field into the page. && What is the direction of force on the charges in the wire? The direction of the force on moving charges in a magnetic field is given by the right-hand rule. If you point your right thumb in the direction of the conventional current (which is the direction of motion of the positive charges), and your fingers in the direction of the magnetic field, then your palm points in the direction of the force. In this case, the current is from left to right, and the magnetic field is into the page. If you point your right thumb to the right and curl your fingers into the page, your palm points upwards. So, the force on the positive charges in the wire is upwards