Science Buddies: "Ask an Expert"

I am testing what manipulations can affect a magnet's strength. I have electrocuted a magnet and put neodymium magnets against a weaker one and have done other various manipulations to the magnet. I have a few questions about my science project and magnet's.
1) What are the materials and manipulations that can weaken a magnet?
2) What do you think would happen after I electrocute a magnet?
3) Are ceramic block magnet's a strong or weak type of magnet?
4) What is the best way to measure a magnet's strength?
5) What makes one magnet stronger than another?
For my experiment I used an EMF tester to find each ceramic block magnet's strength.
-Thanks

Hi -matissechaf-

Welcome to the Ask an Expert forums. I'm not sure what you mean by electrocuting a magnet--can you please explain what you did in more detail? But, I can help with your other questions! Also - I'm assuming you are talking about permanent magnets, not electromagnets, in my answers.

1) Here are a couple of things: Heating a magnet can weaken it. A permanent magnet can lose its magnetization above its Curie temperature. Dropping a magnet can sometimes also weaken its magnetization, depending on the kind of magnet. Shock waves can weaken or completely demagnetize magnets.

3) Ceramic block magnets are not particularly strong for their size. A similarly sized neodymium magnet, for example, will be much stronger than a ceramic block magnet.

4) This blog post talks about different ways of measuring the strength of magnets: http://www.kjmagnetics.com/blog.asp?p=magnet-grade.

5) A number of factors can make one magnet stronger than others. The following two websites have some good explanations as to why this is:
http://www.thenakedscientists.com/HTML/ ... tion/1852/
http://science.howstuffworks.com/magnet.htm