Liquid Mercury vortex in a magnetic field

In this experiment we see that half of a copper globe is anodized with nickel metallic paint and connected to an electric wire in a direct current pole. In the center of the container there is a brass bolt electrically isolated from the container and connected to another pole of the direct current. At the base of the wooden support there is a large magnet which generates a magnetic attraction. Liquid mercury weighing just over 1 kg is poured into the container. When current flows through the two conductors, it generates a strong magnetic field that supports the system. This favorable condition causes mercury to rotate since it is a very conductive metal. For the success of the experiment it is necessary to have liquid mercury not less than 1 kg. The experiment does not work with gallium, as it is a less fluid metal. The voltage source is given by a 2 volts 45 amps transformer driven by a direct current inverter. The current absorbed for operation is approximately 38 amps. The speed of rotation of the mercury varies according to the weight and the voltage supplied. * System doesn’t work in alternating current.