microphones

• microphones use the generator effect to convert the pressure variations in sound waves into variations in current in electrical circuits
• how microphones work:

  • sound waves hit the diaphragm
  • this causes the diaphragm and coil of wire to move back and forth, through the magnetic field produced by the magnet
  • as it does so, a potential difference current is induced in the wire
  • this induced potential difference switches direction as the coil moves backwards and forwards through the magnetic field
  • the frequency and amplitude of sound waves will determine how much the diaphragm vibrates and therefore determine the frequency and amplitude of the current
  • the changing pattern of pd is passed through an amplifier and loud speaker