<P> A magnet keeper, also known historically as an armature, is a paramagnetic bar made from soft iron or steel, which is placed across the poles of a permanent magnet to help preserve the strength of the magnet by completing the magnetic circuit; it is important for magnets that have a low magnetic coercivity, such as alnico magnets . </P> <P> Keepers also have a useful safety function, as they stop external metal being attracted to the magnet . </P>

How does the presence of the keeper alter the magnetic field of the horseshoe magnet