$A$ thin rod of length $L$ has magnetic moment $M$ when magnetised. If the rod is bent into a semicircular arc,what is the magnetic moment in the new shape?

Two identical thin bar magnets each of length $l$ and pole strength $m$ are placed at right angles to each other with the north pole of one touching the south pole of the other. The magnetic moment of the system is:

$A$ long magnetic needle of length $2L$,magnetic moment $M$,and pole strength $m$ is broken into two equal pieces at the middle. The magnetic moment and pole strength of each piece will be

The direction of the magnetic field lines of a bar magnet is:

Two equal bar magnets are kept as shown in the figure. The direction of the resultant magnetic field,indicated by the arrow head at the point $P$,is (approximately):

Use:
$(i)$ the Ampere's law for $\vec{H}$ and
$(ii)$ continuity of lines of $\vec{B}$,to conclude that inside a bar magnet,
$(a)$ lines of $\vec{H}$ run from the $N$ pole to $S$ pole,while
$(b)$ lines of $\vec{B}$ must run from the $S$ pole to $N$ pole.