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.
Answer: Every amplifier (speaker) has an electrical current. When the current is changing, it produces a magnetic field. To make the cone (or panel) of the speaker move, magnets are used to create an opposing magnetic field which creates vibrations. These vibrations are the sound we hear. Speakers often contain large magnets inside of them, as a larger opposing magnetic field creates more vibrations. The larger the magnet, the louder the speaker.