Magnetic field intensity is defined as

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

A bar magnet of length $10 \,cm$  and having the pole strength equal to $10^{-3}$ weber is kept in a magnetic field having magnetic induction $ (B)$  equal to $4\pi \times {10^{ – 3}}$ Tesla. It makes an angle of $30°$  with the direction of magnetic induction. The value of the torque acting on the magnet is

What is pole strength of a bar magnet ? Show the magnetic dipole moment in terms of pole strength.

The dipole moment of a short bar magnet is $1.25\, A-m^2$. The magnetic field on its axis at a distance of $0.5$ metre from the centre of the magnet is