The key difference between bar magnet and electromagnet is that the bar magnet has a permanent magnetic field whereas the electromagnet has a temporary magnetic field.
A magnet is a material that can produce a magnetic field. The magnetic field is invisible. But, it can produce a force that pulls on other ferromagnetic materials such as iron. Also, it can either attract or repel other magnets. Furthermore, there are two major types of magnets as permanent and temporary magnets. A bar magnet is a good example of a permanent magnet whereas an electromagnet is an example of a temporary one.
CONTENTS
1. Overview and Key Difference
2. What is a Bar Magnet
3. What is an Electromagnet
4. Side by Side Comparison – Bar Magnet vs Electromagnet in Tabular Form
5. Summary
What is a Bar Magnet?
A bar magnet is a permanent magnet that can create its own persistent magnetic field. The lines of the magnetic field of this magnet forms closed lines. Above all, the field direction is outward from the north pole and goes into the south pole of the magnet. Ferromagnetic materials can be used to make bar magnets.
Figure 01: A Bar Magnet
The magnetic field is strongest inside the magnet. When considering the external magnetic field, the strongest is near the poles. The north pole of one magnet can attract the south pole of another magnet. However, the north pole repels the north pole of another magnet and vice versa. We can easily trace out the magnetic field lines of these magnets using a compass. The needle of the compass rotates until it lines up with the magnetic field lines of the magnet.
What is an Electromagnet?
An electromagnet is a type of temporary magnet that can produce a magnetic field in the presence of an electric current. It is temporary because the magnetic field disappears when we turn off the electric current. Also, these magnets typically contain a wire wound to into a coil. Here, the current that passes through the wire creates a magnetic field.
Figure 02: An Electromagnet
And, this magnetic field is concentrated in the hole in the centre of the wound coil. Often, the coil is wound surrounding a magnetic core. Also, this magnetic core is a ferromagnetic material. Therefore, it can produce a strong magnetic field.
The main advantage of this type of magnets is that we can quickly change the magnetic field by controlling the electric current that passes through the wire. However, one disadvantage is that this needs a continuous power supply to maintain the magnetic field.
What is the Difference Between Bar Magnet and Electromagnet?
A bar magnet is a permanent magnet that can create its own persistent magnetic field whereas an electromagnet is a type of temporary magnet that can produce a magnetic field in the presence of an electric current. Therefore, the key difference between bar magnet and electromagnet is that bar magnet has a permanent magnetic field whereas electromagnets have a temporary magnetic field. Furthermore, we cannot change the magnetic field of a bar magnet quickly as we wish but with electromagnets, it is possible by controlling the electric current that passes through the wire. So, this also a difference between bar magnet and electromagnet. Moreover, we can use a bar magnet as it is but the electromagnets always need a power supply to create the magnetic field.
Further facts about the difference between bar magnet and electromagnet is shown in the below infographic.
Summary – Bar Magnet vs Electromagnet
Both bar magnets and electromagnets are common types of magnets that can attract or repel things. The key difference between bar magnet and electromagnet is that the bar magnet has a permanent magnetic field whereas the electromagnet has a temporary magnetic field.
Reference:
1. “Bar Magnet.” Magnets and Electromagnets. Available here
2. “Electromagnet.” Wikipedia, Wikimedia Foundation, 9 Oct. 2018. Available here
Image Courtesy:
1.”MagnetEZ”By Eurico Zimbres FGEL/UERJ (CC BY-SA 2.0 br) via Commons Wikimedia
2.”Simple electromagnet2″By Berserkerus at ru.wikipediaderivative work (Public Domain) via Commons Wikimedia
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