How a Speaker Works

Speakers are used in portable radios, telephones, stereos, i.e., anywhere electricity is used to produce sound. A common loudspeaker consists of a permanent, magnet surrounding an electromagnetic coil. The coil generates a magnetic field that switched its polarity (north and south) when alternating current passes into it. The changes alter the attraction or repulsion of the coil magnet to the permanent magnet causing the coil magnet to move. The movement of the coil causes a diaphragm to move which creates the sound waves we hear.

credit: ScienceVIEW staff

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