Magnetism and Matter

A cylindrical magnet has a length of 15 cm and diameter 3 cm . If it has uniform magnetisation of $4.0 \times 10^3 \mathrm{Am}^{-1}$, then magnetic dipole moment is

A short bar magnet of magnetic moment of $0.15 \mathrm{~J} / \mathrm{T}$ is placed in a uniform magnetic field of 0.4 T . The potential energy of the magnet in unstable equilibrium is

The susceptibility of a magnetism at \(300 \mathrm{~K}\) is \(1.5 \times 10^{-5}\). The temperature at which the susceptibility increases to \(4.5 \times 10^{-5}\) is

Susceptibility of ferromagnetic substance is

A bar magnet suspended by a horse's hair lies in the magnetic meridian where there is no twist in the hair, on turning the upper end of the hair through \(150^{\circ}\), the magnet is deflected through \(30^{\circ}\) from the meridian. Then...

The horizontal and vertical components of earth's magnetic field at a place are \(0.3 \mathrm{G}\) and \(0.52 \mathrm{G}\). The earth's magnetic field and the angle of dip are

A bar magnet of pole strength \(10 \mathrm{~Am}\) is cut into two equal parts breadthwise. The pole strength of each magnet is