The ultimate individual unit of magnetism in any magnet is called

The magnetic dipole moment of a short magnetic dipole at a distant point along the equator of the magnet has a magnitude of $X$ in $SI$ units. If the distance between the point and the magnet is halved,then the magnitude of the dipole moment will be

If two identical bar magnets,each of length $l$,pole strength $m$ and magnetic moment $M$ are placed perpendicular to each other with their unlike poles in contact,the magnetic moment of the combination is

If a piece of metal is thought to be a magnet,which one of the following observations would offer conclusive evidence?

$A$ permanent magnet:

$A$ thin rod of length $L$ is magnetized and has a magnetic moment $M$. The rod is then bent into a semicircular arc. The magnetic moment in the new shape is