Why does conducting liquid moving in a loop produce DC

[Richie Smash]

Hi suppose you have a conducting liquid in a strong magnetic field, and this is pumped in a continuous loop through two electrodes, why does this produce a D.C current?

My thinking is a simple answer, and that is that the D.C current is produce because the fluid is moving in one direction steadily.

Would it be possible to get this same conducting fluid in the magnetic field to produce A.C instead? I am thinking I would need a special pump to pump the fluid in two different directions.

The set up could be two permanent magnets, a holder to hold an element of fluid and the electrodes, and copper wire connecting it to a load.

 

[sophiecentaur]

You are describing an example of Magnetohydrodynamics (see this link). The effect can be used for propulsion or for producing an electric current with any moving conducting fluid and a magnetic field.
The same effect can usually be achieved by using metal rather than a fluid and you get more out of it. But it does have its uses, where a high speed plasma is available or when you want to measure the speed of a boat through seawater, for instance.