This Circular Coil on a Base allows you to to observe static magnetic fields generated by a constant flowing current which affects the disposition of iron filings.
A coil of wire through which a current can be passed is mounted on a plastic base and surrounds a sheet on which iron fillings can be placed. This coil can be used with classical iron fillings for magnetic field pattern study and also with a compass to see the magnetic effect of current similar to a Tangent Galvanometer.