A bar magnet of magnetic moment $M$ and moment of inertia $I$ is suspended in a uniform magnetic field $B$. If it is displaced slightly from its equilibrium position, its time period of oscillations for small angular displacement $heta$ is $T_1$. Now, if another identical magnet is glued to the first magnet along its length with the like poles together, the new time period of oscillations for small angular displacement is $T_2$. The ratio $\frac{T_1}{T_2}$ is:

A bar magnet of magnetic moment $M$ and moment of inertia is freely suspended such that the magnetic aries is in the direction of magnetic meridian. If the magnet is displaced by a very small angle $({\rm{heta }})$; the angular acceleration is [Magnetic induction of earth’s horizontal field $= {B_H}$]

A bar magnet of magnetic moment ${10^4}J/T$ is free to rotate in a horizontal plane. The work done in rotating the magnet slowly from a direction parallel to a horizontal magnetic field of $4 imes {10^{ - 5}}T$ to a direction $60^\circ$ from the field will be

The torque on a bar magnet due to the earth’ magnetic field is maximum when the axis of the magnet is

When a bar magnet is placed at ${\rm{9}}{{\rm{0}}^{\rm{o}}}$ to uniform magnetic field, it is acted upon by a couple which is maximum. For the couple to be half of the maximum value, it is to be inclined to the magnetic field at an angle is

Rate of change of torque $au$ with defelection ${\rm{heta }}$ is maximum for a magnet suspended freely in a uniform magnetic field of induction $B$, when

The unit of magnetic moment is:

A bar magnet is placed in the position of stable equilibrium in a uniform magnetic field of induction $B.$ If it is rotated through an angle $180^\circ ,$ then the work done is ($M =$ Magnetic dipole moment of bar magnet)

The couple acting on a bar magnet in a uniform magnetic field is independent of:

A magnetic dipole of moment $M$ is placed in a uniform magnetic field $B$. The work done in rotating the dipole from an initial position parallel to the field to a final position $heta$ degrees to the field is $W$. The torque required to hold the dipole at this position is:

A bar magnet when placed at an angle of $30^\circ$ to the direction of magnetic field induction of $5 imes {10^{ - 2}}{\rm{\;T}},$ experiences a moment of couple $25 imes {10^{ - 6}}{\rm{\;N}} - {\rm{m}}.$ If the length of the magnet is 5 cm, its pole strength is