If a piece of metal was thought to be magnet, which one of the following observations would offer conclusive evidence
It attracts a known magnet
It repels a known magnet
Neither (a) nor (b)
It attracts a steel screw driver
A bar magnet is placed north-south with its north pole due north. The points of zero magnetic field will be in which direction from the centre of the magnet
Two small bar magnets are placed in a line with like poles facing each other at a certain distance $d$ apart. If the length of each magnet is negligible as compared to $ d,$ the force between them will be inversely proportional to
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 identical magnetic dipoles of magnetic moments $1.0 \,A-m^2$ each, placed at a separation of $2\,m$ with their axis perpendicular to each other. The resultant magnetic field at a point midway between the dipoles is
The direction of line of magnetic field of bar magnet is