_Experimenting with Electricity
More than one hundred years ago—in 1822, to be exact a college professor in Denmark was talking to his students about electricity. Very little was known in those days about the mysterious currents which flow through wires, but many men were deeply interested in the subject. The Danish professor, whose name was Oersted, was describing the latest experiments in electricity. He was about to perform a demonstration which would enable his students to understand what he was talking about.
On the table before the professor was some wire connected to a battery. A magnetic compass needle was also standing there. The compass needle was not part of the experiment; it had probably been used before and had been left there, unnoticed. Oersted connected the wire to the battery, so that a current began to flow. Then a strange thing happened.
Nobody remembers what Oersted was talking about. All eyes were suddenly fixed on the compass needle. Without having been touched, it began to move slowly, swinging back and forth a little. That was no apparent reason for its movement. Yet before the very eyes of the surprised teacher and his class something had made the compass needle move.
After many more experiments, Oersted came to an interesting conclusion. He stated that when an electric current passes through a wire, the wire becomes a magnet. This theory explained what had happened to the compass needle. As electricity flowed from the battery through the copper wire, the magnetism of the wire caused the needle to move. The wire was affecting the needle just as a bar magnet would.
Using Oersted’s Discovery
Perhaps you are thinking that Oersted’s experiment was not very exciting. What difference does it make to know that when an electric current flows through a wire, the wire is like a magnet? There is nothing very new about magnetism. But the experiment has made a great deal of difference in the lives of all of us. Walk to the light switch and turn on the light; you are using one of the results of Oersted’s work. Step on the starter of your father’s automobile; Oersted helped to make that possible, too. Almost every time you use current electricity, you depend in part on what happened that day in the Danish professor’s laboratory. One thing leads to another when scientists are at work. The movement of a magnetic needle in 1822 starter a whole chain of discoveries and inventions which we are using today.
May increase your knowledge!
Thank you very much. . .
“Gerald S. Craig and John Urban”,
Professor of Sciences
_Our world of science