State the direction of the magnetic dipole moment (from $S$ to $N$ pole of the magnet) and write the unit of the magnetic dipole moment.

$A$ bar magnet of magnetic moment $5 \,Am^{2}$ is placed in a uniform magnetic induction $3 \times 10^{-5} \,T$. If each pole of a magnet experiences a force of $2.5 \times 10^{-4} \,N$, then the magnetic length of the magnet is: (in $\,m$)

$A$ short bar magnet has a length $2l$ and a magnetic moment $10 \text{ Am}^2$. Find the magnetic field at a distance of $z = 0.1 \text{ m}$ from its centre on the axial line. Here,$l$ is negligible as compared to $z$.

$A$ straight magnetic strip has a magnetic moment of $44 \text{ Am}^2$. If the strip is bent in a semicircular shape,its magnetic moment will be . . . . . . . $\text{Am}^2$ (Given $\pi = \frac{22}{7}$)

Write a brief history of magnets.

In the following figures,the lines of magnetic induction due to a magnet $SN$ are given by: