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Loudspeakers

Physics: AQA GCSE Higher, topic 7.2.10

Loudspeakers

A moving-coil loudspeaker or set of headphones has an electromagnet inside a coil. A signal is passed to the loudspeaker in the form of a changing current.

Change in current causes change in magnetic field

Change in current causes change in magnetic field

  • As the direction of the current changes, the direction of the magnetic field induced (brought about) in the electromagnet changes.
Magnetic field change

Magnetic field change

  • A stationary (not moving) magnet repeatedly attracts and repels the electromagnet.
Speakers vibrate

Speakers vibrate

  • This causes the speakers to move backwards and forwards.
Sound is created

Sound is created

  • This creates sound waves.

Test yourself on Loudspeakers

  • Loudspeakers

  • In what form is the signal passed to the loudspeaker?

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