Telephone and its Working
Introduction:
A telephone is a device by which two persons at distant places can directly talk to each other through electric current carrying wires.
Construction:
A telephone system consists of a microphone and a receiver Microphone: The microphone consists of a diaphragm suspended in front of packing of carbon granules.
- Receiver: The receiver has on electromagnet and a diaphragm made of magnetic alloy in front of it.
Working
- Transmission: When someone speaks in front of the microphone, the diaphragm vibrates due to the sound waves. The compressions and rarefactions of the sound waves cause the diaphragm to increase and decrease the pressure on carbon granules. This results in the increment and decrement in the resistance offered by the granules and hence generates fluctuating current. A
- Receiving: At the receiver, the electromagnet receives fluctuating current, which generates a fluctuating magnetic field. The diaphragm in front of the electromagnet also vibrates with different amplitudes and generates sound of same frequency as spoken at the other end.
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