The discovery of the relationship between magnetism and electricity was, like so many other scientific discoveries, stumbled upon almost by accident. The Danish physicist Hans Christian Oersted was lecturing one day in 1820 on thepossibility of electricity and magnetism being related to one another, and in the process demonstrated it conclusively by experiment in front of his whole class! By passing an electric current through a metal wire suspended above a magnetic compass, Oersted was able to produce a definite motion of the compass needle in response to the current. What began as conjecture at the start of the class session was confirmed as fact at the end. Needless to say, Oersted had to revise his lecture notes for future classes! His serendipitous discovery paved the way for a whole new branch of science: electromagnetics.


Around us today are gadgets that works using the concept of passing an electric current to generate a magnetic field around the conductor.

Try to apply this concept to the following applications that we see around us.



Electric bell
http://www.gcsescience.com/pme6.htm



Magnetic Relay
http://www.gcsescience.com/pme7.htm



Circuit breaker
http://www.gcsescience.com/pme8.htm
http://www.pioneerbreaker.com/v/vspfiles/V4_Backup/Tools/howCircuitBreakersWork.htm



Earth Leakage Circuit breaker
http://www.gcsescience.com/pme9.htm