Electromagnets are the type of magnets where magnetic field is produced using the flow of electric current. Until 18th century, the only magnetism known was that of ferrite magnets and of "lodestones", natural magnets of iron-rich ore. The researches undertaken during the period revealed that there was some sort of relation between electricity and magnetism. Scientist knew that lightening could affect the magnetic property of the compass. They discovered that steel, when struck by lightening, could be magnetized and electrostatically charged objects possessed magnetic properties. However, the laws that governed the relationship between electricity and magnetism were still unknown. Scientists were aware of the fact that once the relationship was established, it would open a
gateway for series of invention that would revolutionize the world of
Hans Christian Oersted - Electromagnetism Experiment
In 1820, Hans Christian Oersted, a Danish physicist and chemist, was conducting an electrical experiment in which he placed a current-carrying wire over a compass. The needle flipped perpendicularly to the compass. As the direction of flow of current was reversed, the needle jerked around 180 degrees. He came to a conclusion that relation between magnetism and electricity was not analogous, but closely related. This experiment gave birth to the concept of electromagnetism. The study caused much excitement within the scientist community and there was a flurry of experimental activities in the field of electromagnetic engineering.
Andre Marie Ampere's & Electromagnetism
The French scientist, Andre Marie Ampere felt that if a wire carrying electricity exerted a magnetic force on the needle, two such wires should behave as an independent magnets. Through a series of experiment, he demonstrated that the interaction between these wires was simple and fundamental - parallel (straight) currents attract, anti-parallel currents repel. The force between parallel straight currents was inversely proportional to the distance between them, and proportional to the intensity of the current flowing in each wire.
Thus it was inferred that two different kinds of forces were associated with electricity - electric and magnetic. James Clerk Maxwell further established the relationship between two types of forces. The experiment unexpectedly involved the velocity of the light. This time it was concluded that light was an electric phenomenon. The connection formed the base for the discovery of radio waves, the theory of relativity and a great deal of present-day physics.