A magnet is a piece of metal we have played with since childhood for its unique properties. Magnets are of two types Natural and Artificial Magnets. We use magnets in so many devices that we hardly notice them. Are there natural magnets? Moreover, how are natural magnets different from artificial ones? Let us bring you a detailed article explaining the same.

What Does Magnet Mean?

Magnet is a material that has the property to attract certain materials. It has an invisible field around it, which is called the magnetic field. A magnet has two poles.

Let us see some important terms related to magnetism:

Poles

The ends of a magnet where the magnetic field is concentrated are called poles. Every magnet has exactly two poles. The two poles of a magnet are the North (N) and South (S) poles. N pole of one repels or pushes away the N pole of another magnet. The same happens with S poles. The N pole of one attracts the S pole of another magnet

Magnetic Field

It is a region in space surrounding a magnet where the magnet has an influence. If an iron piece comes within this field, it gets attracted. The magnetic field is a vector quantity that means it has a direction. A magnetic field line is an imaginary line that emerges from the North Pole and enters the magnet through the South Pole. The field exists within the body of the magnet also. So, the field line is a closed loop.

Properties of Magnets

(a) Magnets have the property of attracting certain metals. Hence, it is called attractive property.
(b) Similar or like poles (N and N, or S and S) of two magnets repel or move away from each other.
(c) Dissimilar or unlike poles (N and S) of two magnets attract each other.
(d) A magnet always aligns itself in the North-South direction. Therefore, it is called directive property.
(e) The poles cannot be isolated from each other, and they exist in pairs. They are called magnetic dipoles. When a magnet breaks in half it becomes two separate magnets with their own two poles, this is called the pair property of the magnets.

Do Natural Magnets Exist?

Yes, they do. Yes, it is. Then how else humans would have known that such things exist?
A long time ago, some shepherds found it difficult to walk with their shoes fitted with iron nails. It was found that the abundant iron ore found there had some magnetic properties.
A natural magnet is called lodestone, a naturally magnetized piece of magnetite, that attracts iron, so it is technically a magnet.

People found that these “magical stones” had two properties
(i) They could attract iron pieces.
(ii) When they were suspendedly with a string, they always pointed in the North-South direction.
Sailors and travellers used this property to find the direction using a sharpened lodestone tied to a string.

A natural magnet is an oxide of iron, called iron oxide, with a chemical formula of \(F{e_3}{O_4}.\)

Is Earth A Huge Magnet?

Yes, it is. As we know when a magnet is leftly suspended it aligns in the North-South direction. What makes it do so? The Earth acts as a huge magnet with a field surrounding the entire globe.
One of the theories about its existence is that the liquid molten iron outer core rotates around a solid inner core. This creates an electric field, thereby causing a magnetic field.
The magnetic South Pole is in the direction of the geographic North Pole. The attractive property of magnets makes the North Pole of magnet orient in the direction of the magnetic South Pole of the earth (or the geographic North).

Uses of Earth’s magnetic field:
(a) A compass makes use of this property to show directions to sailors, travellers, and pilots.
(b) There are theories that migratory birds use the earth’s magnetic field to find their way as they fly for thousands of kilometres while migrating.
(c) The magnetic field of the earth is responsible for the protection of life. This field diverts away from the harmful radiations from the sun.

What Are Artificial Magnets?

As the name suggests, they are made by humans. Artificial magnets can be permanent or temporary.

Permanent Magnets

The magnetic property of these magnets is not lost once they are magnetized.
Certain metals like iron, nickel, cobalt and their alloys can be made into magnets. Such elements are called ferromagnetic materials. These materials are strongly attracted by magnets and can be magnetized. There are two types of ferromagnetic materials, soft and hard.

Hard ferromagnetic materials are used to make permanent magnets. Let us see how some materials can get magnetized:
(a) As we know that all matter is made of atoms with negatively charged electrons orbiting the nucleus.
(b) When a charge in motion it creates an electric current. And this circular movement of current creates a magnetic field. So both electric fields and magnetic fields are connected.
(c) In all materials, the magnetic fields of each atom point in all directions, cancelling each other.
(d) In ferromagnets that are magnetized by an external force, all these individual fields line up in the same direction. So, the sum of tiny individual magnets due to each atom will add up to form one single entity as a magnetic object.

There are four types of commercially available permanent magnets. They are made using alloys of ferromagnetic materials.
(i) \(AlNiCo\) – Aluminium-Nickel-Cobalt magnets
(ii) \(Fe\) – Ferrite magnets made of \(F{e_3}{O_4}\)
(iii) \(NdFeB\) – Neodymium-Iron-Boron. These are the strongest permanent magnets.
(iv) \(SmCo\) – Samarium-Cobalt magnets

Temporary Magnets

These are made of soft ferromagnetic materials. As a result, they do not retain their magnetism for a long time. Instead, they get their magnetic property in the presence of a strong permanent magnet. Once the field is removed, they lose their ability to attract.
(i) An iron nail attached to a magnet will behave like a magnet and attract smaller iron objects. However, if it is separated from the magnet, then the nail loses its magnetism, and the iron pieces will fall.
(ii) A chain of paper clips can be made by connecting one to another, with one of them attached to a permanent magnet. Separate that clip from the magnet, all else will drop down.

What Is An Electromagnet?

The “electro” in electromagnet shows its connection with electricity. It is a temporary magnet that is created by passing a current through a coil. The coil is called a solenoid. The solenoid is wound over a soft ferromagnetic material, and a direct current is passed through it. The current creates a magnetic field and magnetizes the material. The magnetism stays here until the current is passing in it. Once the current is switched off, the electromagnet loses its magnetism, and the things which are connected to it will dropdown.

Permanent Magnet vs Electromagnet

Permanent Magnet	Electromagnet
Magnetism is permanent.	Magnetism is temporary.
It is made of hard ferromagnetic materials.	It is made of soft ferromagnetic materials.
It is created by using other magnets or electric current.	It is created by using current through a coil.
Magnetic strength is fixed.	Magnetic strength can be changed by varying the current.
The position of the poles is fixed.	The poles can be reversed by reversing the current direction.

Applications of Magnets

(a) Both permanent and electromagnets are used in speakers that convert electricity to sound.
(b) Weak permanent magnets are used to close refrigerator doors.
(c) A compass shows direction.
(d) Computer hard disks are made of magnetic materials.
(e) Motors that convert electrical energy to mechanical energy and generators that convert mechanical energy to electrical energy use electromagnets. Very small devices use permanent magnets.
(f) Electromagnets are used to lift iron objects, to separate iron filings from other mixtures.
(g) Doctors use Magnetic Resonance Imaging (MRI) scanning to study problems in the human body. In addition, magnetic therapy is used to treat many ailments.

Natural and Artificial Magnets: FAQs

Q.1. What are the methods of making a magnet?
Ans: One method is by rubbing a permanent magnet against a magnetic metal such as iron. Another method is to place the metal inside a coil and then pass direct current through the coil.

Q.2. The earth attracts things to itself. Is it because of its magnetic field?
Ans: Attraction of the earth is due to the gravitational force and not due to the magnetic field.

Q.3. What is the comparison between a natural magnet and an artificial magnet?
Ans: A natural magnet is a permanent magnet and is found in nature. Artificial magnets can be permanent or temporary. It is created by human intervention.

Q.4. Why do cranes use electromagnets in place of permanent magnets?
Ans: Certain cranes are used to pick up iron scrap. After picking and moving them, they need to be deposited in another place. In electromagnets,  just by switching off the electric supply, it is easy to drop the scrap but it is difficult to separate the scrap from the permanent magnet.

Q.5. Is the earth a natural magnet?
Ans: Yes, The earth has a magnetic field. Its South pole is oriented towards the geographic North pole.

We hope this detailed article on Natural and Artificial Magnets helps you in your preparation. If you get stuck do let us know in the comments section below and we will get back to you at the earliest.