How can a permanent magnet be demagnetized?
A.Cut the magnet in half.
B.Heat the magnet up
C.Strike the magnet with a heavy blow
D.both b and c
You will find the answer if you read this:
http://my.execpc.com/~rhoadley/magcare.htm
To demagnetize a permanent magnet, you can choose from a couple of methods. One approach is to heat the magnet up to a high temperature, which disrupts the alignment of the magnetic domains within the magnet, causing it to lose its magnetism. Another method is to strike the magnet with a heavy blow, which can also disrupt the alignment of the magnetic domains and result in demagnetization.
So, the correct answer to the question is option D, which states that both heating the magnet up and striking it with a heavy blow can demagnetize a permanent magnet.
If you want to learn more about magnet care and demagnetization techniques, you can refer to the following link: http://my.execpc.com/~rhoadley/magcare.htm.