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Here are 2 concise excerpts from a book I have been reading:-

1.A permanent magnet produces its own magnetic field. An induced magnet is a material that becomes a magnet when it is placed in a magnetic field. Induced magnetism always causes a force of attraction. When removed from the magnetic field an induced magnet loses most/all of its magnetism quickly

  1. The force between a magnet and a magnetic material is always one of attraction.

I am trying to link the two excerpts that have been given separately. What I understand is stated below:-

  1. A permanent magnet produces its own magnetic field(excerpt 1)
  2. This permanent magnet's magnetic field can induce a magnetic material(not magnet) to become a magnet(excerpt 1)
  3. The poles on the induced magnet are induced opposite to the poles on the permanent magnet
  4. As the poles are induced opposite, the force between the magnet and former magnetic material(now induced magnet) is attractive(excerpt 2)
  5. As the induced magnet is taken away from the permanent magnet-it loses it magnetism and hence, is not a magnet(excerpt 1) and hence, returns to being a magnetic material.

First of all, is my understanding accurate? Secondly, does that mean the way that magnets attract magnetic materials(not magnets though) is by turning them to induced magnets?

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  • $\begingroup$ For 1) Yes. For 2) one of the ways to state magnetization can be the way you have stated it. Look into "magnetic domains". $\endgroup$ Commented May 27, 2018 at 8:00
  • $\begingroup$ please could you tell me about that... $\endgroup$ Commented May 27, 2018 at 8:10
  • $\begingroup$ in simplified terms relevant to the question $\endgroup$ Commented May 27, 2018 at 8:10
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    $\begingroup$ > "Induced magnetism always causes a force of attraction." Not true. There are diamagnetic materials, such graphite or bismuth. $\endgroup$ Commented May 27, 2018 at 9:34
  • $\begingroup$ Many materials will remain magnetic after being subjected to a magnetic field. If you stroke a needle with one end of a bar magnet several times, you will see that the needle remains magnetic. See hysteresis at [codecogs.com/library/physics/magnetism/magnetic-hysteresis.php]. $\endgroup$
    – S. McGrew
    Commented May 27, 2018 at 13:16

2 Answers 2

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Magnetism is related to the alignment of the magnetic dipole of the involved subatomic particles. Electrons, as well as protons and neutrons obey a magnetic dipole moment. This phenomenon is intrinsic, means, it exist independent of external factors.

Below certain - and individual for each material - temperature each material with aligned subatomic particles remain as a permanent magnet. And on the other hand any permanent magnet loses its magnetism under the influence of heat, strong and/or alternating magnetic fields or simply under mechanical vibrations. This happens, because in the described cases the self-alignment (self-inductance) of the involved subatomic particles is not strong enough against the increasing chaotic atomic vibrations with increasing temperature.

A permanent magnet produces its own magnetic field.

More precise, permanent magnetism occurs if the magnetic alignment of subatomic particles is stable against surrounding influences. Magnetism respectively magnets were observed because the field induces not only inside the material (between the subatomic particles). The magnetic field continues outside the materials boundaries and this is called a permanent magnet.

This permanent magnet's magnetic field can induce a magnetic material(not magnet) to become a magnet.

Depending on the strength of the used magnet and depending on the strength of the atomic structure and the molecular and lattice structure of the influenced material, this material can become very different variants of magnetism:

Types of magnetism Wikipedia

The poles on the induced magnet are induced opposite to the poles on the permanent magnet

As the poles are induced opposite, the force between the magnet and former magnetic material(now induced magnet) is attractive

These statements are not correct because where are a lot of different phenomena of induced magnetism, see the previous explanations.

As the induced magnet is taken away from the permanent magnet-it loses it magnetism and hence, is not a magnetand hence, returns to being a magnetic material.

This is not correct again because in some cases the material remain a magnet, see the explanations above and the link to WP.

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It is not true that induced magnetism always leads to attraction For example a pencil lead can be levitated above an array of magnets It is true that attraction of an originally non-magnet object to a magnet is due to the non-magnet becoming an induced magnet

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