An electric current has the power to create a magnetic field, and this is the concept that electromagnets capitalize on. An electromagnet is essentially a magnet that operates on electricity. Unlike a permanent magnet, an electromagnet's strength can be modified by adjusting the amount of electric current that flows through it. The magnetism disappears once the current is stopped.
This characteristic gives electromagnets an edge over permanent magnets, as controlling the electric current also means controlling the magnetic field. In other words, the strength of the magnetic field is directly proportional to the strength of the electric field. Interestingly, the poles of an electromagnet can be switched by reversing the flow of electricity .
Electromagnets are typically constructed from a coil of wire wound in a series, which is more effective in generating a magnetic field than a straight wire. This effect can be amplified by winding the wire tightly around a core made of a magnetic material, like iron. In the absence of an electric current, this iron core is not magnetic.
Properties of a Magnet
Magnets have several interesting properties:
Attraction – Magnets attract ferromagnetic materials such as iron, nickel, and cobalt.
Repulsion – Magnets repel and attract each other based on their poles: like poles repel, unlike poles attract.
Direction – A freely suspended magnet will always point in the north-south direction.
How Electromagnets Work
So, how exactly do electromagnets work? To understand this, let's consider the iron core. Why doesn't it generate a magnetic field when it's not influenced by an electric current?
In a normal state, the atoms in the iron are randomly oriented, and their individual magnetic fields cancel each other out. When an electric current is introduced, these atoms begin to align in the same direction. Their combined magnetic fields create a strong overall magnetic field. As the current increases, so does the degree of alignment, resulting in a stronger magnetic field. Once all the atoms are perfectly aligned, increasing the current will not further affect the magnetic field. This state is known as saturation.
A magnet that consists of a piece of iron or steel surrounded by a coil is known as an electromagnet. The metal becomes magnetic when an electric current is passed through the coil.
What are the properties of a magnet?
A magnet has three properties and that are attractive prosperity, repulsive property and directive property.
What is a magnet?
An object which is capable of producing magnetic fields and attracting unlike poles and repelling like poles.
Write some uses of permanent magnets.
Permanent magnets find applications in generators, electric accelerators, and electric motors.
What are the disadvantages of an electromagnet?
Electromagnets can store huge amounts of energy in their magnetic field. If the electric current is interrupted, the energy will discharge. Also, they heat up very fast and consume a lot of electricity.