Magnetic and electric fields are some of the most interesting concepts found on the earth. The interplay between these two things is one of the reasons that magnetic and electric fields are used for many things from powering motors to recording sound and information. Electromagnetism is also widely used in a hospital's equipment and is vital for the survival of many people everyday. Electromagnetism is essential to so many functions of our everyday lives and to many industries livelihoods; it is now hard to think what life would be like without these forces.
One of the most common uses of the properties of electromagnetism is in common speakers. In a speaker there are a few main parts including a cone, a voice coil, and a permanent magnet. The ends of the voice coil are connected to the back of a panel receiver or stereo and the receiver sends a signal through the voice coil which interacts with the magnetic field of the magnet which produces an alternating force that pushes and pulls on the cone. This pushing and pulling creates sound waves.
Some of the more significant uses of electromagnetism are such as in magnetic resonance imaging or MRI's. when a patient receives and MRI he/she is put into a large tube which is like a giant solenoid with super conducting wire and produces a very powerful magnetic field. In this field, atoms of some molecules in the body can be made to give off small radio like transmissions. The strength of the magnetic field inside the solenoid can be varied in order to detect different molecules in different parts of the body as well. With this, it is possible to produce a computer generated resonance image. These pictures can help doctors to come up with images that can accompany those that would be produced y an X-Ray.
Television screens and computer monitors use solenoids to produce images by exerting magnetic forces on moving electrons also. In a television there is an electron gun that fires a narrow beam of electrons at the screen of a tube.