Home > Encyclopedia of Science > Magnetic Recording/Audiocassette

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• History of magnetic recording
• Types of magnetic recording machines

Audiocassette tape recorders are widely used to record and play back music or speech. Information is stored on a narrow ribbon of plastic tape that has one side coated with a magnetic material consisting of magnetically active particles, most commonly iron oxide and chromium dioxide. As the tape passes around the five magnetic heads of a tape recorder, sound is recorded, replayed, or erased according to the heads that are activated.

A recording head (a small electromagnet) magnetizes the passing tape in such a way that the magnetic particles on it are realigned in a pattern that corresponds to the loudness and frequency (rate of vibration) of

incoming sounds. The resulting pattern remains on...