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.
Inside a speaker, an electromagnet is placed in front of a permanent magnet. The permanent magnet is fixed firmly into position whereas the electromagnet is mobile. As pulses of electricity pass through the coil of the electromagnet, the direction of its magnetic field is rapidly changed.peakers come in all shapes and sizes, enabling you to listen to music on your iPod, enjoy a film at the cinema or hear a friendâs voice over the phone.
When the electrical current flowing through the voice coil changes direction, the coil's polar orientation reverses. The voice coil is a basic electromagnet. If you've read How Electromagnets Work, then you know that an electromagnet is a coil of wire, usually wrapped around a piece of magnetic metal, such as iron.he field acts just like the magnetic field around a permanent magnet: It has a polar orientation -- a north end and and a south end -- and it is attracted to iron objects. But unlike a permanent magnet, in an electromagnet you can alter the orientation of the poles.