A bar magnet having centre $O$ has a length of $4 $ $cm. $ Point $P_1$ is in the broad side-on and $P_2 $ is in the end side-on position with $OP_1 = OP_2 = 10$ metres. The ratio of magnetic intensities $H$ at $P_1$ and $P_2$ is

Two identical short bar magnets, each having magnetic moment $M,$ are placed a distance of $2d $ apart with axes perpendicular to each other in a horizontal plane. The magnetic induction at a point midway between them is

When the $N-$pole of a bar magnet points towards the south and $S-$pole towards the north, the null points are at the

The ultimate individual unit of magnetism in any magnet is called

Points $A$ and $B$  are situated along the extended axis of $2\, cm$  long bar magnet at a distance $x $ and $2x$ $ cm$  respectively. From the pole nearer to the points, the ratio of the magnetic field at $ A$ and $B$ will be

The small magnets each of magnetic moment $10 \,A-m^2$ are placed end-on position $0.1\,m$  apart from their centres. The force acting between them is....$N$