Making a Magnet by Electric method
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| Electromagnet making process |
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| Electronagnet |
Wind a good length of insulated copper wire around a steel bar which is to be magnetised. Connect the ends of the wire to the poles of a battery. When the electric current passes through the copper wire the steel bar becomes a magnet. (fig). If a soft iron bar is used. It becomes a strong magnet temporarily. It loses its magnetism as soon as the current in the copper wire is switched off. Such temporary magnets are called electromagnets.
An electromagnet is a device in which magnetism is produced by an electric current.
British electrician, William Sturgeon invented the electromagnet in 1825. The first electromagnet was a horseshoe-shaped piece of iron that was wrapped with a loosely wound coil of several turns. When a current was passed through the coil; the electromagnet became magnetized and when the current was stopped the coil was de-magnetized. Sturgeon displayed its power by lifting nine pounds with a seven-ounce piece of iron wrapped with wires through which the current of a single cell battery was sent.
Sturgeon could regulate his electromagnet; this was the beginning of using electrical energy for making useful and controllable machines and laid the foundations for large-scale electronic communications. Five year later an inventor called Joseph Henry - made a far more powerful version of the electromagnet. American, Joseph Henry(1797-1878), demonstrated the potential of Sturgeon's device for long distance communication by sending an electronic current over one mile of wire to activate an electromagnet which caused a bell to strike. Thus the electric telegraph was born.
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