Two identical thin bar magnets each of length $l $ and pole strength $m$ are placed at right angle to each other with north pole of one touching south pole of the other. Magnetic moment of the system is
$ml$
$2\,ml$
$\sqrt 2 \,ml$
$\frac{1}{2}\,ml$
Two short magnets with their axes horizontal and perpendicular to the magnetic meridian are placed with their centres $40\, cm$ east and $ 50\,cm$ west of magnetic needle. If the needle remains undeflected, the ratio of their magnetic moments ${M_1}:{M_2}$ is
Which statement is correct
Figure shows a small magnetised needle $P$ placed at a point $O$. The arrow shows the direction of its magnetic moment. The other arrows show different positions (and orientations of the magnetic moment) of another identical magnetised needle $Q$.
$(a)$ In which configuration the system is not in equilibrium?
$(b)$ In which configuration is the system in $(i)$ stable, and $(ii)$ unstable equilibrium?
$(c)$ Which configuration corresponds to the lowest potential energy among all the configurations shown?
The distance of two points on the axis of a magnet from its centre is $10 \,cm$ and $20 \,cm$ respectively. The ratio of magnetic intensity at these points is $12.5 : 1. $ The length of the magnet will be......$cm$
Two identical bar magnets with a length $10 \,cm $ and weight $50 \,gm$-weight are arranged freely with their like poles facing in a inverted vertical glass tube. The upper magnet hangs in the air above the lower one so that the distance between the nearest pole of the magnet is $3\,mm.$ Pole strength of the poles of each magnet will be.......$ amp × m$