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

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)

A short bar magnet with its north pole facing north forms a neutral point at $P$ in the horizontal plane. If the magnet is rotated by $90^o$ in the horizontal plane, the net magnetic induction at $P$ is (Horizontal component of earth’s magnetic field = ${B_H}$)

The magnetic potential at a point on the axial line of a bar magnet of dipole moment $M$ is $V$. What is the magnetic potential due to a bar magnet of dipole moment $\frac{M}{4}$ at the same point

Magnetic intensity for an axial point due to a short bar magnet of magnetic moment $M$ is given by

Give the characteristics of magnetic field lines.