My problem comes from this thread: Does a rotating disk develop a potential difference between the centre and rim?
My issue is that I don't see why the assumption of equilibrium commented by Cag must be done. I mean: how do we know that we should expect the electrons to be in equilibrium? Isn't it possible that a steady state current is produced by the electrons which are thrown away from the disk by the centrifugal force? I know that the drag forces in the case of an applied electric field lead the electrons to move really slowly due to the collisions with the metal lattice, but still I don't see why a current is impossible to be produced.
Another question that I make to myself (and to you) is the following: is the electric force produced by the center of the disk at the rim stronger along the disk itself or along the conducting wire? If the answer to the second question is positive, the electrons might jump the potential barrier at the rim and a DC current might be set up.
I must admit that this problem has troubled me since long, because I still see holes in the answers I find.