Magnetism: Properties, Effects & Uses - 65 Chars

[dibilo]

Homework Statement:: Is magnetism a property of materials? Can magnetism be increased, decreased or even completely removed from a material?
Relevant Equations:: Nil

Dear seniors,

This isn't my homework but this simple word "magnetism" has been bothering me for some time.

I know that a magnet can be weakened by hitting and by heating.

I also know that magnetism allows for magnets to interact with ferromagnetic objects as well as other magnets. They are able to do so because at atomic level, the poles are aligned in the same way.

So my question is, when a magnet is being heated and when the poles of the atoms are in disarray, can I say that the magnet has lost its magnetism? Is this an accurate way of saying?

Also, what happens when a magnet attracts a magnetic material?

Does the magnetic material at the same time also exerts magnetic force of attraction on the magnet too?

Thanks a lot!

 

[anuttarasammyak]

So my question is, when a magnet is being heated and when the poles of the atoms are in disarray, can I say that the magnet has lost its magnetism? Is this an accurate way of saying?

Molecules keep their magnetic properties even in heated condition. Heat disturbs arrangement of molecules so that cancellation take place and total sum of magnetism is zero.

 

[dibilo]

So is it fair to say that heat can cause a magnet to lose its magnetism?

Also for part 2 of my question, when a magnet interacts magnetic material, eg a piece of iron, is the attraction mutual or is it only the magnet exerting magnetic force on the iron?

 

[anuttarasammyak]

Curie temperature, https://en.wikipedia.org/wiki/Curie_temperature , would tell you more on your question.

Newton's 3rd law or action-reaction law on mechanics applies to magnetic force also. Magnetic force is mutual.

 

[Mister T]

Also, what happens when a magnet attracts a magnetic material?

Does the magnetic material at the same time also exerts magnetic force of attraction on the magnet too?

It's easy enough to demonstrate that a piece of steel will exert a force on a magnet. All you have to do is bring the piece of steel close to the magnet and see that the magnet is pulled by the piece of steel.

 

[anorlunda]

So is it fair to say that heat can cause a magnet to lose its magnetism?

Here's a neat little demo.