The electromagnet - Telegraph - Old technology but principle! is not old always young and continuous


we know magnet attract small places of iron to it, and will continue to do so, day in and day out, year after year. In short, it is a permanent magnet, and as such has relatively little practical value.

Now by using Oersted’s discovery and results of further researches by faraday, a piece of iron which has no magnetic properties whatever can instantly be turned into a magnet by winding a wire around it and sending an electric current through the wire.



While on the face of it this does not seem to be very important, you can readily see that if the iron becomes a magnet when the current flows through the coil around the iron, and ceases to be a magnet when the current stops, motion in distant places can caused by merely pressing a button and closing an electric circuit.

We can, for example, pick up a needle or nail in Chicago by pressing a button in New York if we have electric current and a wire running from New York to Chicago and if that wire is connected to an electromagnet in Chicago.



 While it may not be important to pick up a needle or a nail, we can rig up an electromagnet which will pull a needle to it and produce a clicking sound by pressing and releasing a button in New York.

This is precisely the principle of the telegraph. The telegraph in principle is nothing more than an electromagnet over which a steel bar is free to move up and down.

When no current flows through the coils the bar is forced up by a spring. When current flows through the coils the iron is magnetized and it attracts the steel bar above it, producing a distinct clicking sound. As soon as the current stops the bar is forced back.

If the current is controlled by a key which when pressed down produces a current and when released stops it, it follows that every time the key is presses down in New York a click will be heard in Chicago, and every time it is released another click will be heard, caused by the steel bar springing back to its original position. As you know the length of time between clicks determines what are known as dots and dashes; a short click is a dot and a long click a dash.

Two systems of dots and dashes are in common used in telegraph- the Morse code and the continental code. The electromagnet is one of man’s most important inventions. It is used in the dynamo, the motor, the telephone, radio, television, the talkies, the bell, block signals and modern devices are based on the electromagnet principle. Now a day’s modern people can’t known about the telegram, they knows telegram messenger only.

The electromagnet - Telegraph - Old technology but principle! is not old always young and continuous The electromagnet - Telegraph - Old technology but principle! is not old always young and continuous Reviewed by knowledge people creators on December 10, 2019 Rating: 5
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