# Confusion with displacement current

I'm currently studying maxwell's equations in class, and my professor has explained the concept of displacement currents. The idea makes sense to me -- I mean, after all, isn't that entirely how a capacitor works? But one thing that doesn't click for me is: can you ever have electrical current (as in regular current; charge flowing; $$\frac{dQ}{dt}$$) AND displacement current in the same place, at the same time? Why/why not?

(If the question isn't phrased well enough, my apologies. I'd be happy to clarify. In the mean time, my question could be simplified to the following scenario: consider charged particles (like electrons) flowing through a conductive wire. Is there BOTH displacement current AND "regular" electrical current in that wire? Why/why not?

My intuition is that you can't, but I can't help thinking about the fact that currents are "driven" by an EMF, which is in essence a potential difference, which implies the existence of an electric field wherever there is current, which then leads me to believe that we could find the displacement current of that same electric field.

• a capacitor that is filled with a regular polarizable dielectric works that way but how does an unfilled capacitor work? How does the current in the wires stay divergence-free between the plates? Yes, charge accumulates on the plates but there is also an induced fluctuating magnetic field between the plates. There is no displacement current in the wire but between the plates. In the old days, some people were even teaching that, by analogy, displacement current is the polarization current of the vacuum. Commented Nov 13, 2023 at 15:16
• A capacitor with a "lossy" dielectric can be modeled as an ideal capacitor in parallel with an ideal resistor. Commented Nov 13, 2023 at 16:49