Magnet is a physical object that can generate a magnetic field around itself, and this field is called Magnetic Field. This magnetic field is responsible for attracting unlike poles and repelling like poles. In other words, a magnet has the power to draw in magnetic materials toward itself and push away those materials that possess similar magnetic properties. The study of magnets is important for Class 6, Class 8, Class 10, and Class 12.
In this article, we are going to learn about what is a magnet, the properties of magnets, the poles of magnets, the magnetic field of magnets, types of magnets, and the applications of magnets.
Table of Content
What is a Magnet?
Magnet is a material that attracts or repels any other similar kind of material in its surroundings. This attraction or repulsion is due to the creation of a magnetic field around the magnet. The strength of the magnetic field is stronger near the magnet and decreases as we go away from it. Hence, the strong attraction and repulsion is felt near the magnet. There are different types of magnets based on nature such as Permanent Magnets, Temporary Magnets, and Electromagnet. Magnets are also of different shapes; based on shape they are classified as bar magnets, spherical magnets, and u-shaped magnets.
Magnet Definition
A Magnet is defined as a physical object that generates a field around itself and exerts a force of attraction or repulsion on a material of the similar kind.
Properties of Magnet
The following are the basic properties of a magnet:
- If you dip a magnet into iron filings, you’ll see that the filings stick to the ends of the magnet. This happens because the attraction is strongest at the poles of the magnet.
- Pairs of magnetic poles always exist.
- Whenever a magnet is suspended freely in mid-air, it always aligns with the Earth’s magnetic field. The end pointing toward the geographic North Pole is known as the North Pole, and the end pointing towards the geographic South Pole is known as the South Pole.
- Opposite poles attract, while similar poles repel.
- The magnetic force between two magnets increases as the distance between them decreases.
Poles Of Magnet
The Poles of a Magnet are the end points of magnets. There are two poles of a magnet namely North Pole and South Pole. There are two laws of attraction of poles which are stated as follows
- Opposite Poles attract each other i.e. North Pole of a Magnet will attract South Pole of other magnet
- Similar Poles repel each other i.e. North will repel north and south will repel south.
How to identify Poles of a Magnet?
The magnetic pole is the region where the external magnetic field is the strongest at each end of a magnet.
- The planet Earth possesses a magnetic north pole that attracts the south pole of a Magnet to point downwards.
- Similarly, it also possesses a magnetic south pole that attracts the north pole of a magnet to point downwards.
When suspended in the Earth’s magnetic field, a bar magnet aligns itself in a north-south direction. A north magnetic pole is the term given to the north-seeking pole of the magnet or any similar pole. Similarly, a south magnetic pole is the term given to the south-seeking pole of the magnet or any pole similar to it. Unlike poles of different magnets tend to attract each other, while like poles repel each other. Visualizing the magnetic poles is easy with a bar magnet. The poles of a permanent magnet are the two ends of the magnet. Using curved lines with arrows, the force exerted by a magnet is represented. These curved lines with arrows are known as magnetic field lines and the magnetic field surrounding the magnet. The direction of the magnetic force, from the North Pole to the magnet’s South Pole, is shown by the arrows on the magnetic field lines.
Magnetic Field Of Magnet
Magnetism acts upon the region surrounding a magnetic material or a moving electric charge, which is called the Magnetic Field. The Magnetic Field is a vector field that can be observed through magnetic forces in proximity to a magnet, electric current, or changing electric field. The movement of electric charges and intrinsic magnetic moments of elementary particles, which is known as spin, produces the Magnetic Field. The Magnetic Field and electric field are components of the electromagnetic force, which is one of the four fundamental forces of nature and are interrelated.
Magnetic Field Lines
An alternative method to represent information contained within a magnetic vector field is through field lines. These lines are imaginary and used as a visual tool to describe the direction of magnetic force on a north monopole at any given position. The density of the lines indicates the magnitude of the field. When we examine a magnet, the magnetic field is more robust and crowded near the poles, while away from the poles, it is weaker, and the lines are less dense.
Properties of Magnetic Field Lines
There are following properties of Magnetic Field Lines
- Magnetic Field Lines are imaginary in nature
- They never intersect each other
- A tangent drawn at any point of magnetic field line represent the direction of magnetic field at that point
- Magnetic Field Lines are denser near the poles and farthest at in between the poles
- The direction of magnetic field lines is from North to South Pole outside the magnet and south to north inside the magnet.
Types of Magnets
There are three types of magnets, and they are as follows:
- Permanent Magnet
- Temporary Magnet
- Electromagnets
Permanent Magnet
When a material is magnetized, it acquires magnetic properties that allow it to attract or repel other magnetic materials. However, not all magnetized materials retain their magnetic properties. Permanent magnets, on the other hand, are those types of magnets that maintain their magnetic properties even after the magnetizing force is removed. They are commonly used in a wide range of applications, including electric motors, generators, and magnetic storage devices.
Here are some methods to demagnetize permanent magnets:
- Subjecting the magnets to extreme temperatures.
- Hammering the magnets can loosen the magnetic attraction between their atoms.
- Rubbing one magnet against another can weaken its magnetic strength.
- There are four types of permanent magnets.
- Ceramic or ferrite
- Alnico
- Samarium Cobalt (SmCo)
- Neodymium Iron Boron (NIB)
Temporary Magnet
It is possible to magnetize temporary magnets, such as iron nails and paper clips, in the presence of a magnetic field. However, these magnets will only maintain their magnetic property as long as the magnetic field is present. Once the field is removed, the magnetic property of these temporary magnets will be lost.
Electromagnets
An electromagnet is comprised of a metal core made of iron and a coil of wire wrapped around it. When an electric current passes through the wire, a magnetic field is produced, causing the material to act like a magnet. The strength of the magnetic field can be adjusted by managing the electric current.
Learn More, Permanent Magnets and Electromagnet
Magnets Based On Shape
Magnets don’t have uniform shapes and sizes. Based on different shapes, they are classified into various categories. Let’s learn more about the different shapes of magnets.
Bar Magnet
A bar magnet is a ferromagnet. It is a rectangular piece made from steel, iron or any other ferromagnetic material/ bar magnet that shows the properties of a permanent magnet. A bar magnet has two poles, namely the north and a south pole. If a bar magnet hangs freely, it automatically aligns itself so that the northern pole of the bar magnet faces toward the earth’s magnetic north pole.
There are two types of bar magnets based on their magnet shape. These two types are:
- Rectangular Bar Magnet: Magnetic strength and magnetic field of a rectangular bar magnet are more significant than other magnets. Rectangular bar magnets are in the manufacturing as well as engineering industries.
- Cylindrical Bar Magnet: Cylindrical bar magnets are also known as rod magnets. The magnetism property of this magnet is higher than other magnets as its thickness is more significant than its diameter. Cylindrical bar magnets are popular in research, experimental, education and other industries.
Spherical Magnets
The magnet is a spherical magnet in a sphere in form. Spherical magnets are also known as ball magnets. The configuration of the polarity of these magnets is similar to that of earth. The concentration of magnetic fields is higher at the north pole as well as the south pole. Spherical magnets can attach like beads when two or more spherical magnets are together. Spherical or ball-shaped magnets are widely used in consumer products, magic hobbies, electronics, R&D and many more.
Horseshoe Magnets
The magnet shape of a horseshoe magnet is U-shaped or shaped like a horseshoe. The Horseshoe magnet was invented in 1825 by William sturgeon. The most significant advantage of a horseshoe magnet is its stronger magnetic field than many others. This is because the magnetic poles of a horseshoe magnet are much closer to each other. Horseshoe magnets pick up large pieces of metals that are heavy.
Disc Magnets
A disc magnet is a circular magnet that is thin and flat. The thickness of a disc magnet shoe does not exceed its diameter. It is a common and versatile magnet. If a hole is drilled, then a disc magnet is recessed in the hole. They are used for holding applications as well as in cup assemblies. It has a north pole and a south pole. They are widely used in industries and markets.
Characteristics of Magnet
The magnet is a fascinating object with several distinctive characteristics.
- Magnet possesses an attractive property, which is evident by the strong magnetic strength at the ends of its poles. Magnet has a directive property that helps to identify which pole is north and south by suspending the magnet in mid-air.
- The law of magnetic poles states that like poles repel while unlike poles attract.
- Another notable feature of the magnet is its pair property. When a magnet is cut into two pieces, each piece will have both the North Pole and the South Pole.
- Finally, the sure test of magnetization is conducted to ascertain if a given rod is magnetized or not, by observing either the attraction or the repulsion of the iron rod and magnet.
These unique characteristics of the magnet make it a useful tool in various fields, including science, engineering, and medicine.
Magnetic Materials
The Magnetic Materials are classified into three types namely
- Diamagnetic Materials
- Paramagnetic Materials
- Ferromagnetic Materials
Diamagnetic Materials
Diamagnetic Materials are those substances in which the spin of the electrons are paired and hence there is no magnetization in presence of a magnet. In presence of external magnetic field the spin of the electrons arrange themselves in a direction opposite to that of the magnetic field. In general they are repelled by the magnetic field. Examples of Diamagnetic Materials include Mercury, Copper etc.
Paramagnetic Materials
Paramagnetic Materials are those materials which get weakly magnetized in the presence of external magnetic field. In paramagnetic materials, spin of the electrons are randomly organized and when magnetic field is applied few of them get aligned in the direction of magnetic field exhibiting partial magnetization. Examples of Paramagentic Materials include Magnesium, Lithium, Molybdenum etc.
Ferromagnetic Materials
Ferromagnetic Materials are those materials which get strongly magnetized in the presence of magnetic field. In Ferromagnetic Materials, spin of the electrons are already aligned hence they get spontaneously magnetized when they come under the influence of magnetic field. Examples of Ferromagnetic Materials include Iro, Cobalt and Nickel
Uses of Magnets
The following are the uses of magnets:
- Magnets have various applications, such as constructing magnetic needles and mariner’s compasses.
- Permanent magnets are utilized in generators, electric accelerators, and electric motors.
- Electromagnets find their use in speakers, electric bells, and electric cranes.
- Additionally, magnets can be used to separate iron filings from other solid mixtures.
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Magnet: FAQs
1. Define Magnet.
A magnet is a physical object that can generate a magnetic field around itself. This magnetic field is responsible for attracting unlike poles and repelling like poles.
2. How many types of Magnets are there?
There are three types of magnets: permanent magnet, temporary magnet, and electromagnet.
3. What are Temporary Magnets?
Temporary Magnets are those which hold magnetic property for very small period of time. It is possible to magnetize temporary magnets, such as iron nails and paper clips, in the presence of a magnetic field. However, these magnets will only maintain their magnetic property as long as the magnetic field is present. Once the field is removed, the magnetic property of these temporary magnets will be lost.
4. What are Permanent Magnets?
Permanent magnets are those types of magnets that maintain their magnetic properties even after the magnetizing force is removed.
5. What are Electromagnets?
Electromagnets comprised a metal core made of iron and a coil of wire wrapped around it. When an electric current passes through the wire, a magnetic field is produced, causing the material to act like a magnet. The strength of the magnetic field can be adjusted by managing the electric current.
6. What are the Magnetic Properties of a Bar Magnet?
The following are the basic properties of a magnet:
- Magnetic poles always exist in pairs.
- Similar poles repel while opposite poles attract.
7. What are the Uses of Magnets?
The following are the uses of magnets:
- Magnets are used for constructing magnetic needles and mariner’s compasses.
- Permanent magnets are used in generators, electric accelerators, and electric motors.
- Electromagnets find application in speakers, electric bells, and electric cranes.
- Magnets are used to separate iron filling from other solid mixtures.
8. What is Magnetic Field?
Magnetic Field is the region around a magnet in which it exerts a force on other magnet.
9. What is Magnetic Field Line?
Magnetic Field Lines are the imaginary lines used to represent the magnetic field around a magnet.
10. What are some commonly used Magnetic Materials?
Some commonly used magnetic materials are: Iron, Cobalt, Nickel, and other rare earth metals
11. What is the Science behind Magnet?
The science behind magnet lies in the arrangement of spin of the electrons of the materials. The alignment of spin decided the magnetic property of a material. Based on this, the magnets are classified in Diamagnetic, Paramagnetic and Ferromagnetic Materials which are discussed above in the article.