According to Fleming left hand rule when a current-carrying conductor is placed in a magnetic field a force “F” acts on a conductor which moves the conductor in the magnetic field. The magnitude of the force on the conductor is directly proportional to flux density “B” of the magnetic field and the magnitude of current “I” passing through a conductor of length “L” which is constant.

The line of magnetic flux or forces travels from the North to the South Pole. A current-carrying conductor placed in a magnetic field observed a Force that depends upon the direction of the current. Line of magnetic field or flux “ ”, the direction of current “I” through conductor and force “F” are perpendicular with each other.
