Can a weak magnetic field demagnetize a permanent magnet with a stronger magnetic field?

Question

oneowone · Answer

Besides, temperature, and slamming a magnet with a hammer or dropping it on the floor what else would effect and demagnetize a magnet?

anonymous · Answer

It depends on the material of the magnet. In order to demagnetise a magnet, we need to apply a magnetic field in opposite direction. This "backwards" magnetic field is called the "coercivity" of the material. Some materials used to make electromagnets like soft iron core have very less coercivity and even a weak magnetic field may demagnetise them. Others like steel require high magnetic fields.

oneowone · Answer

Suppose we have a strong magnet like Neodymium and exposed it to a weak magnetic field, and the weak external field is the opposite pole,the magnet should not be effected at all.

oneowone · Answer

the higher the Coercivity the less it is effected.

oneowone · Answer

i guess :)

anonymous · Answer

"Coercivity" or the "opposite field required to demagnetise" has got nothing to do with strength of the magnet. Soft iron forms an a very strong magnet but a comparitively weak magnetic field can demagnetise it. Steel forms comparitively weaker magnet but require stronger coercive fields than soft iron.

oneowone · Answer

Why can a weak magnetic field demagnetize it? Because of the low Coercivity right?

anonymous · Answer

Yes.

oneowone · Answer

Thus a magnet with a high Coercivity like Neodymium can not be effected.