Explain the Gauss' law for magnetic fields. 

Define the Angle of Dip. What happens to angle of dip as we move towards magnetic pole from magnetic equator?

A circular magnet is made with its north pole at the centre, separated from the surrounding circular South Pole by an air gap. Draw magnetic field lines in the gap. Draw a diagram to illustrate the magnetic lines of force between the south poles of two such magnets.

Two small and similar bar magnets have magnetic dipole moment of $1.0 \mathrm{A} {\mathrm{m}}^2$ each. They are kept in a plane in such a way that their axes are perpendicular to each other. A line drawn through the axis of one magnet passes through the centre of the other magnet. If the distance between their centres is $2 \mathrm{m}$, the magnitude of magnetic field at the mid point of the line joining their centres is $\sqrt{x}\times {10}^{-7} \mathrm{Wb} {\mathrm{m}}^{-2}$. Write the value of $x$.

(Take ${\mu }_0=4\pi \times {10}^{-7} \mathrm{H} {\mathrm{m}}^{-1}$)