An electromagnet is a special kind of magnet in which a magnetic field is generated by passing electricity through the coil. The permanent magnets continuously emit the magnetic fields, however, the electromagnets are developed to produce magnetic fields whenever necessary. Their versatility and strength make them suitable for a wide range of applications. The phenomenon of electromagnetism was first discovered by a Danish scientist, Hans Oersted in 1819. During an experiment, Oersted observed the movement in the needle of a magnetic compass when it was brought near a straight wire carrying current. Before the discovery of electromagnetism both magnetism and electricity were treated as a completely separate phenomenon. Later in 1825, William Sturgeon utilized this phenomenon and designed the first usable electromagnet.
The Principle of an Electromagnet: An electromagnet is formed by winding a wire (conductive) around a core of ferromagnetic materials like nickel, cobalt, iron, etc. These ferromagnetic materials are easy to magnetize resulting in the high magnetic field strength of electromagnets. Current passing through the coil produces a magnetic field that encircles the coil carrying current. The magnetic field can be experienced as long as the electricity continues to flow through the coil. The strength of a magnetic field can be increased by using a suitable core material and by increasing the total number of turns and strength of the current flowing through the coil.
Advantages of an Electromagnet: The electromagnets are versatile and have lots of advantages over permanent magnets in terms of their durability, adjustable magnetic strength and better control over the magnetic field. Moving charges are responsible for the magnetic field in permanent magnets. It comes from the movement of electrons in atomic structure. In comparison to a permanent magnet, an electromagnet is capable of producing more powerful magnetic fields. The power of an electromagnet can be modified by modifying the total current it receives, whereas, the permanent magnets have fixed magnetic strength. Unlike the permanent magnet, the magnetic fields of an electromagnet can be switched off whenever not required. Also, the strength of a permanent magnet degrades with time due to exposure to extreme temperatures or wet environment conditions causing corrosion.
Applications of an Electromagnet: Most of the electric appliances require electromagnets. Communication devices like mobile phones rely on the interaction of the phone signal and a magnetic pulse generated by the electromagnets inside the phone. MRI (Magnetic resonance Imaging) machine use electromagnets to generate magnetic waves that penetrate through the body to generate images.
Subscribe to our YouTube video channel to understand basic physics concepts like collision theory, momentum, thermodynamics, laws of motion, kinetic theory and more with engaging video lectures- https://www.youtube.com/watch?v=dxuG5PeNBMo