A magnet is a material or object that produces a magnetic field that pulls on other ferromagnetic materials. The difference between electromagnet and permanent magnet depends on its manufacturing process. The main difference between electromagnet and permanent magnet is that an electromagnet is created by the current running through a coil of insulated wire that is wound around a piece of “soft” magnetic material. A permanent magnet uses a “hard” ferromagnetic material that maintains its magnetism over long periods of time. Let us now understand more about the difference between electromagnet and permanent magnet by studying its basics.
What is Electromagnet?
Electromagnets consist of wire wound into a coil. Now when current passes through the wire it creates a magnetic field. The strength of the magnetic field disappears when the current is turned off. The wire is often turned around a magnetic core made from a soft ferromagnetic or ferrimagnetic material such as iron. One big advantage of an electromagnet is that the alteration of the magnetic field strength is possible by changing the current flow.
What is a Permanent magnet?
As the name suggests, “permanent magnet” means everlasting. It is a metal object made from a material that is magnetized and creates its own persistent magnetic field. Permanent magnets are made from “hard” ferromagnetic materials such as alnico and ferrite which have an inherent magnetic field in their crystalline structure. The common process of making permanent magnets is by heating a ferromagnetic material to a key high temperature.
Difference Between Electromagnet and Permanent Magnet
The important difference between electromagnet and permanent magnet
|Definition||Forms when current passes through a ferromagnetic material.||Forms by heating a material which has inbuilt magnetic properties.|
|Strength||Depends on the current flow. Can produce a strong magnetic field.||Depends on the nature of the material used for creation. Relatively weaker field.|
|Magnetic properties||Can be altered using current.||Once magnetic properties are lost, it becomes useless.|
|Material||Soft material used||Hard material used|
|Field stability||Requires a continuous supply of current for a magnetic field.||No requirement of current to maintain its field effect.|
|Poles||Alteration of Poles is possible by changing coil direction||Alteration of the Poles is not possible.|
We must learn in detail to find out more about the difference between electromagnet and permanent magnet.
An electromagnet produces the magnetic field with the use of electric current. It uses a ferromagnetic or ferrimagnetic material such as iron to form an electromagnet. Electromagnets are made of wire wound into a coil and as current flows magnetic field is created. The main advantage of an electromagnet over a permanent magnet is that we can quickly change the magnetic field by controlling the amount of electric current in the winding.
The magnetic field created by an electromagnet is proportional to both the number of turns in the winding and the current in the wire. Electromagnets are very widely in use in electric and electromechanical devices, such as transformers, relays, motors, loudspeakers, MRI machines, etc. There are three basic types of electromagnets: the robust ones, the superconductors, and finally the hybrids.
A permanent magnet is an object made from a ferromagnetic material that when magnetized remains longlasting. It forms a persistent magnetic field and has a specific north and south pole. Permanent magnets are made from materials such as alnico and ferrite( hard ferromagnetic materials) that are subjected to special processing in a strong magnetic field during manufacturing to align their internal microcrystalline structure.
Process for magnetizing ferromagnetic materials are:
1) Heating the object higher than its Curie temperature, allowing it to cool in a magnetic field and hammering it as it cools.
2) Another method is placing the Ferro material in an external magnetic field. The material retains some magnetism on removal. Vibration also increases the effect.
3) Another method is Stroking. A single touch method and a double touch method are used.
4) An electric current runs through a coil to line up the domains in the material.
There are various places where permanent magnets are useful such as refrigerators, headphones, speakers, hard disk, acoustic transducers, automobiles, motors, etc. There are six types of Permanent Magnets Ceramic, Alnico, Samarium Cobalt, Neodymium Iron Boron, Injection Molded, Flexible.
FAQs about electromagnet and permanent magnet
Q.1. Is Lodestone a permanent magnet?
Answer- The lodestone is an extremely rare form of the mineral magnetite (Fe3O4) that occurs naturally as a permanent magnet. William Gilbert in the sixteenth century scientifically investigated the magnetism property of lodestone and when he defined its ‘poles’ and the well‐known rule that ‘like poles repel, unlike attract’.
Q.2. How does the number of coils affect the strength of an electromagnet?
Answer- Increasing the number of coils, which adds more field lines and makes the electromagnet stronger. Turning coils around and passing a current through them will make a much stronger electromagnet.