Electromagnets are everywhere. You may rarely consider this fact, but every time you crank up your car engine, turn on your laptop or other electronic device or visit the doctor for a thorough body screening, you are putting an electromagnet to work. Electromagnets are used in thousands of devices and perform key functions in advanced technology.
What Is an Electromagnet?
An electromagnet is a magnet that is created when an electric current is applied to a certain material. Electric current creates a magnetic field that can be manipulated by forming a wire into a tight coil, creating layers of magnetic fields and thereby strengthening the magnetic power of the coil. When a core of iron is inserted into the centre of the coil, the magnet is made even stronger. When the electric current is removed, the magnetic properties are lost. By controlling the electric current, the electromagnet can be controlled.
One use of electromagnets that many people rarely get to observe is in industrial lifting. Electromagnets are used extensively in junkyards and in scrap metal refineries to move large piles of old metal. The large electromagnets are composed of a giant iron plate attached to a crane. An electric current is sent to the plate creating a magnet powerful enough to lift tons of metal. The material can then be lifted and transported to a different location for processing.
Magnetic Resonance Imaging
The large medical devices known as MRIs (magnetic resonance image machines) function, as their name implies, through the use of powerful electromagnets. When a person is placed inside an MRI, the machines actually magnetise the atoms in his body. The nuclei of the atom send a magnetic signal to the other components of the machines that produce a scan of the various areas of the body. Doctors can use this image to determine the exact location of problems in the patient and develop a remedy. MRI machines allow for an incredibly detailed view of the inside of a person without using radiation or surgery.
Yes, electromagnets are also used to transport people at very high speeds. Magnetic levitation trains use high-powered electromagnets to move trains at speeds of several hundred miles per hour. The scientific principle that allows for this is called electromagnetic suspension. It allows an object to literally levitate above a surface. Electromagnetic suspension works because an electromagnetically charged object cannot achieve a stable equilibrium inside of an electrostatic field. When the current is constantly altered, the object's magnetic attraction is altered as well. Magnetic levitation in trains allows the vehicle to move rapidly to catch the changing magnetic fields. This form of transportation also saves electricity by allowing magnetic force to do a lot of the work.