What is the working principle of an electromagnet ?

An electromagnet is a type of magnet that is created by applying an electric current to a coil of wire. Its working principle is based on the interaction between electricity and magnetism, as described by the electromagnetic field theory.

The basic working principle of an electromagnet involves the following steps:

Electric Current: When an electric current flows through a conductor (such as a coil of wire), it creates a magnetic field around the conductor. This magnetic field is circular and perpendicular to the direction of the current flow.

Ampère's Circuital Law: The magnetic field produced by the electric current follows Ampère's Circuital Law, which states that the magnetic field strength (measured in units of magnetic flux density called Tesla) is directly proportional to the current flowing through the wire and inversely proportional to the distance from the wire.

Concentration of Magnetic Field: By coiling the wire into a spiral shape (forming a coil or solenoid), the magnetic fields produced by each turn of the wire combine and reinforce each other. This results in a stronger and more concentrated magnetic field inside the coil.

Core Material: To further enhance the strength of the electromagnet, a core material made of ferromagnetic material (such as iron) is often placed inside the coil. Ferromagnetic materials can easily become magnetized in the presence of a magnetic field, thus increasing the overall magnetic strength of the electromagnet.

Switching Current On and Off: The key advantage of an electromagnet is its ability to be turned on and off by controlling the electric current flowing through the coil. When the current is flowing, the electromagnet produces a magnetic field and behaves like a permanent magnet. When the current is turned off, the magnetic field disappears, and the electromagnet loses its magnetism.

Electromagnets have numerous practical applications, ranging from industrial uses (such as lifting heavy objects in scrapyards and magnetic separators) to everyday devices (such as electric door locks and relays). Their controllable magnetism makes them versatile tools in various fields.