Ratio of magnetic intensities for an axial point and a point on broad side-on position at equal distance d from the centre of magnet will be or The magnetic field at a distance d from a short bar magnet in longitudinal and transverse positions are in the ratio

Two identical short bar magnets are placed at $120^{\circ}$ as shown in the figure. The magnetic moment of each magnet is $M$. Then the magnetic field at the point $P$ on the angle bisector is given by

Magnetic intensity for an axial point due to a short bar magnet of magnetic moment $M$ is given by

A magnetic needle suspended horizontally by an unspun silk fibre, oscillates in the horizontal plane because of the restoring force originating mainly from

$(a)$ Magnetic field lines show the direction (at every point) along which a small magnetised needle aligns (at the point). Do the magnetic field lines also represent the lines of force on a moving charged particle at every point?

$(b)$ Magnetic field lines can be entirely confined within the core of a toroid, but not within a straight solenoid. Why?

$(c)$ If magnetic monopoles existed, how would the Gauss’s law of magnetism be modified?

$(d)$ Does a bar magnet exert a torque on itself due to its own field? Does one element of a current-carrying wire exert a force on another element of the same wire?

$(e)$ Magnetic field arises due to charges in motion. Can a system have magnetic moments even though its net charge is zero?

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....$N$