Fleming's left-hand rule

Fleming’s left-hand rule gives a direction, not the size of the force. It is used for the motor effect; it should not be confused with rules used for electromagnetic induction.

Fleming’s left-hand rule therefore gives opposite force directions on those sides: one side is pushed up while the other is pushed down. Because the forces act on different sides of the coil, they form a turning effect and the coil rotates. This is the principle of a simple electric motor, which transfers electrical energy into movement.