1) The tape recorder which we use to listen songs or record voices works on the principle of electromagnetic induction.
2) It consists of piece of plastic tape coated with iron oxide and is magnetised more in some parts than in others.
3) When the tape is moved past as a small coil of wire (head of the tape recorder), the magnetic field produced by the tape changes, which leads to generation of current in the small coil of wire.
4) This small current will be converted into sound by speaker of varying strengths.
5) Thus the voice will be reproduced from the tape of a tape recorder.