This type of alternating current (AC) motor comprises a static stator (pale grey casing), which contains electromagnets (blue) arranged to form a hollow cylinder. Within the stator sits a moving rotor (shiny), which is mounted on the motor′s shaft. The rotor also contains electromagnets (not seen). To make the rotor turn, the magnetic field of the stator is altered so that the poles of the rotor are attracted by the opposite poles on the stator. As the magnetic field of the stator rotates, the rotor is forced to rotate with it.
Electricity and magnetism go hand in hand. Wherever there is moving electric charge, magnetic effects are present too. Electromagnetism is the physics of the electromagnetic field; it is encompassing all of space, composed of electric and magnetic fields.
Electric field can be produced by stationary electric charges, and gives rise to the electric force, which causes static electricity and drives the flow of electric current in electrical conductors. The magnetic field can be produced by the motion of electric charges, such as an electric current flowing along a wire, and gives rise to the magnetic force one associates with magnets.
The term "electromagnetism" comes from the fact that the electric and magnetic fields are closely intertwined and under many circumstances, it is impossible to consider the two separately. For instance, a changing magnetic field gives rise to an electric field; this is the phenomenon of electromagnetic induction, which underlies the operation of electrical generators, induction motors, and transformers. Oersted was the first scientist to show how a magnetic compass needle deflected due to the presence of an electric current. The reverse is true as well!
We use electromagnets to generate electricity, store memory on our computers, generate pictures on a television screen, diagnose illnesses, and in just about every other aspect of our life that depends on electricity.