ELECTROMAGNET #2

Danish Scientist Hans christian orsed discovered in 1820 that electric currents create magnetic fields. Scientist william sturgeon invented the electromagnet in 1824.His first electromagnet was a-shaped piece of iron that was wrapped with about 18 turns of bare copper wire (insulated wire didn't exist yet). The iron was vanished to insulate it from the windings. When a current was passed through the coil, the iron became magnetized and attracted other pieces of iron; when the current was stopped, it lost magnetization. Sturgeon displayed its power by showing that although it only weighed seven ounces (roughly 200 grams), it could lift nine pounds (roughly 4 kilos) when the current of a single-cell battery was applied. However, sturgeon's magnets were weak because the wire he used could only be wrapped in a single spaced out layer around the core, limiting the number of turns.

Beginning in 1830, us Scientist Joseph henry systematically improved and popularized the electromagnet. By using wire insulated by silk thread, and inspired by schweigger’s use of multiple turns of wire to make a galvanometer, he was creating powerful magnets with thousands of turns of wire, including one that could support 2,063 1b (936 kg). The first major use for electromagnets was in telegraph sounders.