Thus, to produce a strong magnetic field, speakers employed a separate electrical source to provide a steady current to the electromagnet.
(speakers; employed; a separate electrical source; to provide a steady current to the electromagnet) Context(speakers employed,List([42, 59))):(speakers; employed a separate electrical source to provide; a steady current; to the electromagnet)
speakers employed,List([42, 59))
speakers speakers
employed employed a separate electrical source to provide
a separate electrical source to provide a steady current to the electromagnet
a steady current to the electromagnet