Imagine a simple setup. I have a copper disc and another copper element held close to the disc at one of it's sides, this element is stationary but the disc is rotating, the part between the disc and the element that overlaps forms a capacitor. If I put a potential difference (voltage source) across the rotating disc and stationary element the capacitor charges up.
For the stationary copper plate everything is clear but the disc is rotating does that mean that the charge buildup on the disc that faces the charges on the stationary plate are constantly moving their position on the disc surface in order to always be at the position that faces the plate because the E field attracts them there? So even the disc is rotating the charges are moving on the disc surface to stay in a stationary position with respect to the physical disc rotating?