Not all magnets consist of a solid piece of ferromagnetic material. Some of them are made of wire coils. Known as electromagnets, they use electricity to generate a magnetic field. As electricity flows through the wire coils, it becomes magnetized. When the electricity stops flowing through the wire coils, it loses its magnetic field. Below are five fun facts about electromagnets and how they work.
Electromagnets are controllable. This is one of the features that distinguish them from traditional, solid magnets. Other magnets generate a permanent magnetic field. The magnetic field is generated by the ferromagnetic material of which they are comprised. Electromagnets are different because they only generate a magnetic field when electricity flows through the wire coils. By disrupting the flow of electricity through the wire coils, the magnetic field can be disabled.
#2) Discovered In the 19th Century
Electromagnets were first discovered in the 19th century by Danish scientist and researcher Hands Christian Orsted. Orsted found that electricity, when ran through wire coils, produces a magnetic field. About a decade later, a British scientist named William Sturgeon built an electromagnetic out of copper wire. Sturgeon applied a voltage to the coiled copper wire, resulting in the production of a magnetic field.
#3) Adjustable Power Level
Another unique feature of electromagnets is an adjustable power level. The power of their magnetic field can be adjusted by increasing or decreasing the amount of electricity flowing through the wire coils. The more electricity that flows through the wire coils, the stronger the magnetic field will be. Permanent magnets don’t offer an adjustable power level. They produce the same, consistent magnetic field at all times.
#4) Used in MRI Machines
A common application for electromagnetics is magnetic resonance imaging (MRI) machines. MRI machines are medical imaging devices that are used to diagnose injuries and illnesses in people. Most MRI machines rely on superconducting electromagnets to perform this task. They feature a large coil that’s cooled with helium. The electromagnets in MRI machines are so, strong, in fact, that can typically lift a vehicle. This is why patients are required to remove all jewelry before entering an MRI machine.
#5) Used in Generator
In addition to MRI machines, electromagnets are commonly used in generators. Wind and hydro generators, for instance, typically generate energy through induction. They feature a coil of wire that spins between two magnets. As the wire coil spins, electricity is generated.