This stems from thinking about the question If a perfect conductor were to move, what happens to the electrons?.
Suppose we have a rotating disk with no external magnetic field, so this is not a homopolar generator/Faraday disk experiment. The rotation creates a difference in potential energy between the centre and the rim, so does this mean that if we connect a wire (with suitable brushes) between the centre and the rim electrons will flow from the centre through the disk to the rim then back through the wire? That is, does the rotation create an electrical potential difference between the centre and the rim?
It seems obvious to me that the answer is yes, however I have never seen the calculation done. Attempts to Google it fail because the results are swamped by articles on Faraday disks and/or homopolar generators.
Answer
Electrons in a conducting disk in order to maintain equilibrium will have to have a centripetal force on them equal to the local change in potential energy with respect to a change in radius, that is
$$ m_e\omega^2 r = -e{d\phi\over dr} $$
After integrating, we get a potential difference between the center and a point R out
$$ \Delta\phi = -{m_e\omega^2 R^2\over 2e} $$
A conducting disk spinning at a rate of six million radians per second should generate about one volt of potential ten centimeters out from the center. I hope this was helpful. ;)
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