Describe an activity to show that …

A current-carrying conductor when placed in a magnetic field experiences a force. The  direction  of  the  force  gets reversed  when  the  direction  of  the  current  is  reversed  or  when  the direction of the magnetic field is reversed. The force acting on a conductor is found to be maximum when the current and magnetic field are at right angles to each other. When the conductor is placed parallel to the magnetic field, no force acts on it.

Fleming’s Left-Hand Rule gives the direction of the magnetic force acting on the conductor.

Fleming’s Left-Hand Rule:

Stretch the thumb, forefinger and middle finger of the left hand such that they are mutually perpendicular to each other. If the forefinger points in the direction of the field, and the middle finger in the direction of the current, then the thumb gives the direction of motion or the force acting on the conductor.

The force experienced by a current-carrying conductor in a magnetic field is the underlying principle of an electric motor where electric energy is converted into mechanical energy. Such motors are used to run many electrical appliances, including fans, toys etc.