The telephone ,it barely needs explation ,is a device , the primary funtion of which is to transmit voice over long distances. This is essentially performed by converting the sound signal into a corresponding electrical signal which is then transmitted. Finally at the receiving end , the electrical signal is converted back into sound signal, thus achieving the objective.
What follows is a step by step explanation of the working of a telephone.
When a caller picks up the receiver,the cradle puts on the receiver, i.e it allows a link between the caller's telephone and the exchange, which is realised by a current flowing from the exchange to the caller's telephone, which manifests itself as the dial tone.The caller then dials the number using the dialler.As soon as the first digit is dialed , the dial tone is cut off.The exchange registers the number ,& through a switching mechanism locates the required phone on the network.It then sends it a ringing signal, which then results in the ringing of the ringer at the receiver's end.As soon as the receiver picksup the handset,the cradle puts it on, and a connection is established.
Whenever one of them speaks into the transmitter, it converts the sound sig nal into an electrical signal.This signal is amplified and sent to the receiver's telephone through telephone wires(electric wires).This signal goes to the receiver where it is converted back into a sound signal. And thus effectively , sounds gets transmitted over long distances.
Finally , when the conversation is over , and the cradle is pushed down, the connection is closed, and the original configuration is restored.