A long magnetic needle of length $2\,L$, magnetic moment $ M$  and pole strength $m$ units is broken into two pieces at the middle. The magnetic moment and pole strength of each piece will be

A short bar magnet of magnetic movement $5.25 \times 10^{-2} \;J\, T ^{-1}$ is placed with its axis perpendicular to the earth's field direction. At what distance from the centre of the magnet, the resultant field is inclined at $45^{\circ}$ with earth's field on

$(a)$ its normal bisector and

$(b)$ its axis.

Magnitude of the earth's field at the place is given to be $0.42 \;G$. Ignore the length of the magnet in comparison to the distances involved.

The magnetic field to a small magnetic dipole of magnetic moment $M$, at distance $ r$  from the centre on the equatorial line is given by (in $M.K.S. $ system)

Write the difference between electric field lines and magnetic field lines.

Magnetic field intensity is defined as

A short magnet is allowed to fall along the axis of a horizontal metallic ring. Starting from rest, the distance fallen by the magnet in one second may be.....$m$