A current-carrying conductor placed in a magnetic field experiences a force. The direction of this force depends on the direction of the magnetic field and the direction of the electric current. If the conductor is perpendicular to the magnetic field lines, the size of the force can be calculated using the formula F = B x I x L where B is the magnetic field strength, I is the electric current and L is the length of the conductor in the magnetic field.

This effect is sometimes called the “motor effect” as it is the basic principle behind an electric motor.