<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> A magnet is a material or object that produces a magnetic field . This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, and attracts or repels other magnets . The overall strength of a magnet is measured by its magnetic moment or, alternatively, the total magnetic flux it produces . The local strength of magnetism in a material is measured by its magnetization . </P> <P> A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field . An everyday example is a refrigerator magnet used to hold notes on a refrigerator door . Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include iron, nickel, cobalt, some alloys of rare - earth metals, and some naturally occurring minerals such as lodestone . Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic, all other substances respond weakly to a magnetic field, by one of several other types of magnetism . </P>

Any material that pulls iron to it is a