The ultimate individual unit of magnetism in any magnet is called

If a magnet of pole strength $m$ is divided into four parts such that the length and width of each part is half that of the initial one,then the pole strength of each part will be

An iron rod of length $L$ and magnetic moment $M$ is bent in the form of a semicircle. Now its magnetic moment will be

Out of the following units,the $WRONG$ unit of magnetic dipole moment is

$A$ steel wire of length $l$ and magnetic moment $M$ is bent into a semicircular arc of radius $R$. The new magnetic moment is

The force between two identical bar magnets whose centres are $r \ m$ apart is $4.8 \ N$,when their axes are in the same line. If the separation is increased to $2r$,the force between them is reduced to . . . . . . $N$.