Cite a Poem From a Book. EasyBib can help you cite a poem from a book, here's how: 1  Type in the ISBN of your text book (find inside the front of the book).  If more than one book is listed, double check the details and click Select on the correct book.
Without electromagnets, the speakers won't work, that is why they are used. Like asking why an engine is used in an automobile, or blades in a fan. Some speakers do you electrostatics to produce the motion needed to produce sound. billrussell42 Â· 7 years ago. Thumbs up. 1.here is an electromagnet attatched to the diaphragm. When current flows through the coil one way it becomes a magnet. since there is a permanent magnet behind the coil, the coil is pulled toward the magnet.
(Most cell phone microphones are condenser/electret microphones, and do not contain a permanent magnet.) Donât forget the speakers in your car. Count each ear-bud in any music playing device you might have. Which ones use neodymium magnets? Usually it's the ones where small size counts. While the huge speaker of a subwoofer might utilize a ceramic magnet, the tiny earbuds you use with your smartphone or mp3 player are likely to use neodymium magnets.