Making and Maintaining Magnets – Introduction and Explanation

Making and Maintaining Magnets  

 Key Concepts

• Methods to make a magnet
• Maintaining a magnet

Introduction

Magnets were found naturally first and then made artificially by people. Later on, people started using magnets for various purposes, such as navigation. However, a magnet can be made out of a piece of magnetic substance such as iron, nickel, steel, etc., using a few things available at home. These magnets should be taken care of in several ways too. In this section, we will be looking at the ways in which magnets are made and maintained. 

Explanation

Making a magnet: 

There are 3 methods by which we can make a magnet. They are, 

1. Single touch method 

2. Double touch method 

3. Using electric current 

Single touch method: 

To make a magnet by single touch method, we need a magnetic material such as an iron bar, a bar magnet and some paper clips (for testing). 

• Take the magnet and place one of its poles on one of the ends of the iron bar. 
• Now, stroke the iron bar using the magnet from one end to another without lifting it. 
• After a stroke, lift the magnet and place it back at the same end. 
• Repeat the steps around 20 to 30 times. 

• Now, check whether the iron bar has become a magnet or not by taking it close to some small iron paper clips. 
• If the iron bar attracts the clips, it becomes a magnet. 
• Otherwise, repeat the same process for some more time. 

Remember to stroke the iron bar using the same pole of the magnet and in the same direction. 

Double touch method: 

Double touch method is a similar method of magnetizing an iron bar. Here, we need two permanent bar magnets, an iron bar and a few iron paper clips (for checking). 

The opposite poles of two permanent bar magnets are placed side by side in the middle of the iron bar. 

The two magnets are then moved towards the ends of the iron bar. 

They are then lifted and brought to the center of the iron bar once again. 

This process should be done at least 20 to 30 times. 

The iron bar has to be brought close to some iron paper clips to check whether it has become a magnet or not. 

If it attracts the paper clips, it has become a magnet. Otherwise, the process should be repeated for some time until it attracts the paper clips. 

Using electric current: 

A magnet that is made using an electric current is called an electromagnet. To make an electromagnet, we need a large iron nail, a copper wire, a switch and a battery. 

• Wind a copper wire around an iron nail at least 10 times. This copper wire now has two free ends. 
• Connect one of the free ends to the positive terminal and the other free end to the negative terminal of the battery. 
• This forms a complete circuit through which current flows. 
• This makes the set-up of the nail wound with copper wire a magnet, called an electromagnet. 

• It attracts small iron objects towards itself. 
• One can also use a switch in this circuit to control the flow of current in the circuit. 
• The iron nail remains magnetized for some time after the switch is turned off. 

Electromagnet vs. permanent magnet: 

• The advantage of an electromagnet over a permanent magnet is that these can be turned on and off when needed. 
• The strength of such magnets can also be varied according to the requirement, which cannot be done in the case of permanent magnets. 

This is the reason why electromagnets are used for various purposes, such as in generators, motors, transformers, magnetic locks, data storage, MRI machines, etc. 

Maintaining a magnet: 

There are a few cautions which should be kept in mind while using permanent magnets. These are as follows: 

1. Magnets should not be hammered. 

2. Magnets should not be heated. 

3. Magnets should not be dropped. 

In all of the above cases, magnets lose their properties. 

Magnets become weak if they are not stored properly. For this, the bar magnets should be kept in pairs with their unlike poles placed together.  There must be a piece of wood separating them from each other. Two pieces of soft iron should be placed across their ends. A piece of iron should be kept across the ends of a horseshoe magnet. 

The magnets should be kept away from cassettes, cell phones, television sets, music systems and computers. 

Question and Answer: 

1. Which of the following objects can be turned into a magnet and which of them cannot? Give reason for your answer. 

• Iron rod 
• A needle 
• A piece of wood 
• An iron nail 

Answer: 

The iron rod, the needle and the iron nail can be turned into magnets by a single touch, double touch methods or by using electricity.  

This is because they are made up of iron and steel, which are magnetic materials. 

The piece of wood cannot be turned into a magnet by any of the above-mentioned methods as it is not a magnetic material. 

Summary

1. There are 3 methods in which we can make a magnet. They are, single touch method,
   double touch method and using electric current.
2. Using these methods, a magnetic material can be turned into a magnet.
3. In single touch method, a permanent magnet is moved on the magnetic material in one
   direction, without lifting, several times.
4. In double touch method, two permanent magnets are moved on the magnetic material
   from its center towards its ends without lifting, several times.
5. When a magnetic material is wound several times using a copper wire, whose ends are
   then connected to a battery, an electromagnet is formed.
6. The magnetization of an electromagnet can be switched on and off and also its strength
   can be varied according to the requirement.
7. Bar magnets should be stored in pairs with opposite pole placed together and a piece of
   wood between them and two pieces of soft iron across their ends.
8. Horseshoe magnets should be stored with an iron piece placed across its ends.
9. The magnets should be kept away from devices such as television sets, music system
   and computer.