Physics Lesson 16.1.4 - How is a Magnet Produced?

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Welcome to our Physics lesson on How is a Magnet Produced?, this is the fourth lesson of our suite of physics lessons covering the topic of Introduction to Magnetism, you can find links to the other lessons within this tutorial and access additional physics learning resources below this lesson.

How is a Magnet Produced?

A magnet can be divided in pieces (as discussed in the above example) to obtain smaller magnets. This process lasts until we obtain a single proton-electron pair. Such pairs known as dipoles are the smallest magnets possible. Dipoles are assumed as enclosed within small rooms called domains where each domain contains a single dipole. In normal conditions, all materials are neutral and their dipoles are randomly oriented as shown in the figure.

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When we allow some electric current flow through material, the dipoles are oriented according the direction of electric current. In this way, a bipolar magnetic material is obtained. The total charge is still zero; this means the object is only magnetised, not electrically charged. This method of magnetisation is known as the electrical method. Look at the figure:

Other ways to obtain a magnet include:

Contact method consisting in touching a magnet with a metal that possesses magnetic properties. In this way, the metal is magnetised after a certain period due to the regular orientation of its dipoles;
Induction method, i.e. bringing a non-magnetized metal near a magnet. After a while, the metal is magnetised, i.e. its dipoles are oriented according the magnetic field lines;
Stroking method. If we strike gently a steel needle by a magnet, the needle is magnetised after a number of strokes.

Demagnetisation, i.e. the process of magnetism removal from a magnetised object, is carried out in one of the three following ways:

By striking the magnet with a hammer. Strong strokes distort the regular orientation of magnetic dipoles, turning the metal in the state is has been prior to becoming a magnet.
By dropping the magnet from a height. This method works in a very similar way to the previous one.
By heating the magnet. Heating an object results in a higher kinetic energy of its molecules. This brings a less regular orientation of dipoles and consequently, a decrease in the magnetic properties of the object.

You have reached the end of Physics lesson 16.1.4 How is a Magnet Produced?. There are 9 lessons in this physics tutorial covering Introduction to Magnetism, you can access all the lessons from this tutorial below.

More Introduction to Magnetism Lessons and Learning Resources

Magnetism Learning Material
Tutorial ID	Physics Tutorial Title	Revision Notes	Revision Questions
16.1	Introduction to Magnetism
Lesson ID	Physics Lesson Title	Lesson	Video Lesson
16.1.1	A Brief History of Magnetism. Natural and Artificial Magnets
16.1.2	Magnetic Field of Magnets and Earth. Magnetic Poles
16.1.3	Magnetic Field Lines
16.1.4	How is a Magnet Produced?
16.1.5	Permanent and Temporary Magnets
16.1.6	The Earth as a Giant Magnet. Two North Poles.
16.1.7	Magnetosphere
16.1.8	Magnetism in Animals
16.1.9	Magnetism in Use

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Magnetism Physics tutorial: Introduction to Magnetism. Read the Introduction to Magnetism physics tutorial and build your physics knowledge of Magnetism
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Continuing learning magnetism - read our next physics tutorial: Magnetic Field Produced by Electric Currents

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