Force between two identical bar magnets whose centres are $r $ metre apart is $ 4.8\, N$ , when their axes are in the same line. If separation is increased to $2r,$ the force between them is reduced to…..$N$

Earth magnetic field at equator is approximately $0.4\,G$ then earth's dipole moment would be (nearly) (ralius of earth $= 6.4 \times 10^6\,m$ )

Give the characteristics of magnetic field lines.

Due to a small magnet intensity at a distance $x$ in the end on position is $9$ $Gauss$. What will be the intensity at a distance $\frac{x}{2}$ on broad side on position….. $Gauss$

Points $A$ and $B$  are situated along the extended axis of $2\, cm$  long bar magnet at a distance $x $ and $2x$ $ cm$  respectively. From the pole nearer to the points, the ratio of the magnetic field at $ A$ and $B$ will be