Magnetism From Electricity:


    1.    Describe Oersted's experiment on currents and magnetic fields and state the principle he discovered.

    2.    Define electromagnetism.

    3.    Explain the structure and use of electromagnets.

    4.    Describe the structure and use of electric motors.

    5.    Distinguish between direct and alternating current.





Oersted’s Discovery.  

As we stated earlier, the source of magnetism ultimately lies in the electrons of the magnetic material.  Therefore, it makes perfect sense that the current flowing through wires also creates magnetic fields.  Oersted discovered this while placing a compass near a wire with current.  He noticed that the current in the wire caused the compass to orient itself 90 degrees from the moving current.  When he switched the the compass also switched.  

Ørsted's experiment 1.    Ørsted's experiment 2.( KGalsgaa/oersted2.gif)



The discovery of the electrons magnetic field led to the production of electromagnets.  Remember that electromagnetism is the relationship between electricity and magnetism.

Electromagnets are made by wrapping wire around a soft iron core.


Electric Motor:

Converts electric energy into mechanical energy.


A galvanometer is an instrument used to detect very small currents.