How does a telephone work?
The fascinating instrument, Telephone, was invented by Alexander Graham Bell in 1876.
The Telephone transmits sound waves in the form of electric currents. The instrument is made up of a receiver and a cradle. The cradle enables us to dial a number while the receiver helps to receive and transmit messages through the earpiece and the mouth piece. When the receiver is lifted, a weak electric current is switched on. When we speak into the mouthpiece, we speak into the mouthpiece, we actually speak into, a tiny carbon microphone. Sound waves hit a diaphragm inside the microphone and it starts vibrating. The carbon granules in it get compressed and alter the electrical resistance of these vibrations. These changes vary an electric current along the telephone line and enters the earpiece at the reviver’s end. Here the varying current makes an electromagnet to vibrate another diaphragm to produce the sound of the caller’s speech.
