I have a capacitor which i just like a plate capacitor, but instead of the upper electrode being a plate it is a point charge Q. the lower plate is held at a fixed potential V=0.
I am supposed to calculate the capacitance of the capacitor.
The Attempt at a Solution
I've used the image method with a negative charge (-Q) at the same distance from the lower plate (forcing V=0 on this plate).
now I wanted to calculate the potential difference between the "plates", but it is obvisously inifinite since as we get closer to the point charge the potential grows like 1/x^2.
and thus C = Q/delta_V = 0
what am I missing?