Magnets and Their Discovery – Discovery & Types of Magnets

Magnets and Their Discovery 

 Key Concepts

• Magnets
• Discovery of magnets
• Magnetic and non- magnetic materials

Introduction

We see various things such as papers stuck to the door of the fridge, paper clips sticking to the magnetic pin holder and magnetic sticks joined to form a structure as shown below. All these objects have small pieces of magnets in them which makes them stick to other iron objects and objects containing magnets. 

Explanation

Magnets: 

A magnet is a material which is capable of attracting things made of or contain iron. Most magnets are made up of iron or an alloy of iron. They are used for many purposes such as credit cards, toys, cassettes tapes etc. They are also used in doorbells, refrigerators, microphones, loudspeakers etc. 

Discovery of magnets: 

• The magnet was first discovered by a shepherd named Magnes, who lived in a place named Magnesia, Greece. 
• He used to take a stick which had a small piece of iron attached to its tip, while taking his herd of sheep and goats for grazing to nearby mountains. 
• Surprisingly, one day he noticed that his stick got stuck to a rock, and it was harder than usual to pull it off. 
• This rock was actually a natural magnet and the tip of the stick got stuck to it as it was made of iron. 
• Rocks like this were named as “Magnetite” perhaps after the name of the shepherd or the place where it was discovered. 
• Such naturally occurring substances which have the property of attracting iron are known as natural magnets. 
• The process of making magnets from pieces of iron was discovered later. 
• The magnets made by such artificial methods are called artificial magnets. 
• These artificial magnets are made in various shapes such as bar magnet, ring magnet, horseshoe magnet, magnetic needle, disc magnet etc. 

Magnetic and non-magnetic materials: 

The materials which get attracted towards a magnet are called magnetic materials. The hammer head, the cast iron pan, the tools, the fridge are all magnetic materials. Steel is a magnetic material as it contains a large portion of iron in it. 

The materials which do not get attracted towards a magnet are called non-magnetic materials. The bed, the clothes, the mirror and all the materials made of plastic are called non-magnetic materials. 

When a magnet is moved in the soil or sand it will be found that some particles of the soil stick to the magnet. Now, shake the magnet gently to remove the excess soil particles. There will be some particles still sticking to the magnet. These particles might be small pieces of iron called iron filings. This process can be used to check whether the soil of some place contains iron or not. 

Question and Answer: 

Identify the magnetic and non-magnetic objects in the image of a geometry box shown below: 

Answer: 

Magnetic materials:  

1. The compass 

2. The divider 

3. The blade of the sharpener 

4. The geometry box 

Non-magnetic materials: 

1. Ruler 

2. Protractor 

3. Set squares 

4. Eraser 

5. The plastic body of the sharpener 

Summary

1. A magnet is a material which is capable of attracting things made of or contain iron.
2. They are used for many purposes such as credit cards, toys, cassettes tapes, doorbells,
   refrigerators, microphones, loudspeakers etc.
3. A magnet was first discovered by a shepherd named Magnes, who lived in a place named
   Magnesia, Greece.
4. Naturally occurring substances which have the property of attracting iron are known as
   natural magnets.
5. The magnets made by man-made methods are called artificial magnets.
6. These artificial magnets are made in various shapes such as bar magnet, ring magnet,
   horse shoe magnet, magnetic needle, disc magnet etc.
7. The materials which get attracted towards a magnet are called magnetic materials.
8. The materials which do not get attracted towards a magnet are called non-magnetic
   materials.