A small magnetised needle $P$ placed at point $O$ and the arrow shows the direction of its magnetic moment. The other arrow show different position (and orientation) of another identical magnets $(Q)$. In which configuration system is not in equilibrium

A short bar magnet has a magnetic moment of $0.48\; J \;T ^{-1} .$ Give the direction and magnitude of the magnetic field produced by the magnet at a distance of $10 \,cm$ from the centre of the magnet on

$(a)$ the axis,

$(b)$ the equatorial lines (normal bisector) of the magnet.

The direction of line of magnetic field of bar magnet is

A bar magnet of magnetic moment $M$ is cut into two parts of equal length. The magnetic moment of each part will be ......... $M$

A short magnet of moment $6.75\, Am^2$ produces a neutral point on its axis. If horizontal component of earth's magnetic field is $5 \times {10^{ - 5}}\,Wb/{m^2}$, then the distance of the neutral point should be.....$cm$

Magnetic moments of two bar magnets may be compared with the help of