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…..$N$

A bar magnet of magnetic moment $3.0\, A-m^2$ is placed in a uniform magnetic induction field of $2 \times 10^{-5}\, T$. If each pole of the magnet experiences a force of $6 \times 10^{-4} \,N$, the length of the magnet is…..$m$

Two magnetic dipoles $X$ and $Y$ are placed at a separation $d$, with their axes perpendicular to each other. The dipole moment of $Y$ is twice that of $X$. A particle of charge $q$ is passing through their mid-point $P$, at angle $\theta  = 45^o$ with the horizontal line as shown in the figure. What would be the magnitude of force on the particle at that instant ? ($d$ is much larger than the dimensions of the dipole)

Two equal bar magnets are kept as shown in the figure. The direction of resultant magnetic field, indicated by arrow head at the point $P$  is (approximately)

Two identical bar magnets are fixed with their centres at a distance $d$ apart. A stationary charge $Q$ is placed at $P$ in between the gap of the two magnets at a distance $D$ from the center $O$ as shown in the figure. The force on the charge $Q$ is