Permanent & Induced Magnets (Edexcel IGCSE Science (Double Award)) : Revision Note

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Permanent & induced magnets

Magnetic materials

Magnetic Materials, downloadable IGCSE & GCSE Physics revision notes

Magnetic materials are attracted to a magnet; non-magnetic materials are not

  • Magnetic materials are materials which are attracted by magnets

    • Being a magnetic material does not mean the material is itself a magnet

  • Very few metals in the periodic table are magnetic, these include:

    • Iron

    • Cobalt

    • Nickel

  • Steel is an alloy which contains iron, so it is also magnetic

  • Magnetic materials will always be attracted to the magnet, regardless of which pole is held close to it

Magnetic Materials Attracted to Magnet, downloadable IGCSE & GCSE Physics revision notes

Magnetic materials attracted to either pole of a magnet

  • To test whether a material is a magnet it should be brought close to a known magnet

    • If it can be repelled by the known magnet then the material itself is a magnet

    • If it can only be attracted and not repelled then it is a magnetic material

  • There are two types of magnets

    • Permanent magnets

    • Induced magnets

Permanent magnets

  • Permanent magnets are made out of permanent magnetic materials, for example steel

  • A permanent magnet will produce its own magnetic field

    • It will not lose its magnetism

Induced magnets

  • When a magnetic material is placed in a magnetic field, the material can temporarily be turned into a magnet.

    • This is called induced magnetism

  • When magnetism is induced in a material:

    • One end of the material will become a north pole

    • The other end will become a south pole

  • Magnetic materials will always be attracted to a permanent magnet

    • This means that the end of the material closest to the magnet will have the opposite pole to magnets pole closest to the material

Inducing magnetism in a magnetic material, downloadable IGCSE & GCSE Physics revision notes

Inducing magnetism in a magnetic material

  • When the magnetic material is removed from the magnetic field it will lose most/all of its magnetism quickly

Worked Example

The diagram below shows a magnet held close to a piece of metal that is suspended by a light cotton thread. The piece of metal is attracted towards the magnet.

WE Magnet question image, downloadable IGCSE & GCSE Physics revision notes

Which of the following rows in the table gives the correct type of pole at X and the correct material of the suspended piece of metal?

 

Type of pole at X

Material of suspended metal

A

North

Nickel

B

South

Nickel

C

North

Aluminium

D

South

Aluminium

Answer: A

  • X must be a north pole

    • The piece of metal is being attracted towards the magnet

    • The law of magnetism states that opposite poles attract

  • The material of the suspended piece of metal is nickel

    • Nickel is a magnetic material (It will experience a force when it is placed in a magnetic field, in this case it is attracted towards the magnet)

  • B is incorrect because X cannot also be a south pole (and hence is a north pole)

    • If the pole at X was a south pole then the piece of metal would be repelled from the magnet because the law of magnetism states that like poles repel

  • C and D are incorrect because aluminium is not a magnetic material

    • A non-magnetic material would be unaffected by the magnetic field produced by the magnet.


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Ashika

Author: Ashika

Expertise: Physics Content Creator

Ashika graduated with a first-class Physics degree from Manchester University and, having worked as a software engineer, focused on Physics education, creating engaging content to help students across all levels. Now an experienced GCSE and A Level Physics and Maths tutor, Ashika helps to grow and improve our Physics resources.

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