# Does there exist a single plate capacitor(conductor)?

Does there exist a single plate capacitor(conductor)? if yes

How will you define the capacitance and potential(difference) of such conductor?

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Wouldn't static electricity (for example on a balloon) count as a single plate "capacitor"? –  fibonatic Feb 11 at 7:26
The term you're looking for is self-capacitance. Look it up, you'll get some insight. –  Nanite Feb 11 at 7:32

A simple example is that of a sphere. One way to find its capacitance is to take the limit of a nested sphere capacitor with radii $a,b$: $$C = \lim_{b\to\infty}\frac{4\pi\epsilon_0}{\frac{1}{a}-\frac{1}{b}} = 4\pi a\epsilon_0\text{.}$$ A van de Graaff generator is a commonly discussed in physics classes, and involves this type of setup.

For a parallel-plate capacitor, however, doing the same gives zero capacitance.

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