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.
Another type of passive transducer is the thermistor. These devices change their resistance value to electricity that flows through them as temperature changes. Thermistors are commonly used in circuits that measure temperature. The speakers in your TV, stereo and car radio convert a varying voltage into sound.