How songs are recorded in a video cassette?
Video tapes are long, thin plastic films coated with a magnetic material, usually iron oxide. Songs are recorded by magnetizing them. The video player has a recording head which comprises a coil of a wire wound around a circular piece of iron with a small gap. Any current passing through the wire would produce a magnetic field around it.
Songs to be stored are converted into electrical signals by a microphone amplified and fed to the recording head. As the current varies in accordance with the image or sound to recorded, it produces a varying magnetic field. To reproduce the signal recorded, the tape is run past the playing head which senses the magnetic field along the tape. This induces a varying current which is amplified and fed to the TV to reproduce the song.