Assertion: dynamic loudspeaker | /r/CapableOf | use magnetic field
Facets:
value: to move a coil
type: PURPOSE
value: to move magnet
type: PURPOSE
Source sentences:
text: The standard dynamic loudspeaker that we know of today was first built in the 1920's and uses a magnetic field to move a coil or magnet which is connected to a diaphragm.