Explain briefly the following terms used in communication system: (i) Transducer (ii) Repeater (iii) Amplification

Transducer- A device which converts one form of energy into another. E.g. in a microphone a transducer converts sound energy into electrical energy.
Repeater - It can be defined as, receiver+amplifier+transmitter.
Amplification- When a signal covers a long distance its strength decreases, therefore its strength should be increased, this is done by the process of amplification. It is clear that amplification means increment of signal strength.