AQA GCSE Physics

Revision Notes

7.1.2 Permanent & Induced Magnets

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

  • 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 (which are not magnets) 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 magnets

  • 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

Types of Magnets

  • 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 on 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?

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

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 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.

Author: Katie

Katie has always been passionate about the sciences, and completed a degree in Astrophysics at Sheffield University. She decided that she wanted to inspire other young people, so moved to Bristol to complete a PGCE in Secondary Science. She particularly loves creating fun and absorbing materials to help students achieve their exam potential.
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