magnetism - the microphone Flashcards
1
Q
how does a moving coil microphone work?
A
- generator effect used
- features of microphone: coil of wire, attached to a thin sheet of plastic (diaphragm), end of coil of wire sits over a permanent magnet
- when sound waves hit the diaphragm, they cause it to vibrate
- now coil of wire moves in and out through the magnetic field. this induces a potential difference across the ends of the wire
- the graph for this shows potential difference switches direction as coil moves back and forth through magnetic field. frequency of changing potential difference is same as frequency of sound waves. changing pattern of pd is now passed through an amplifier and then into a moving coil loudspeaker. massively increases volume of sound
