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.
How relays work. Here are two simple animations illustrating how relays use one circuit to switch on a second circuit. When power flows through the first circuit (1), it activates the electromagnet (brown), generating a magnetic field (blue) that attracts a contact (red) and activates the second circuit (2).ere are two simple animations illustrating how relays use one circuit to switch on a second circuit. When power flows through the first circuit (1), it activates the electromagnet (brown), generating a magnetic field (blue) that attracts a contact (red) and activates the second circuit (2).