Calculating Charge & Electric Energy Above a Plane

AI Thread Summary
A charge "+Q" positioned above an infinite conducting plane leads to a calculated total charge of "-Q" on the plane using the method of images. The stored electric energy is derived as W_{E}=-\frac{Q^{2}}{8\pi\epsilon_{0}d}, which raises concerns about the capacitance being negative. This suggests that the system does not behave like a traditional capacitor, as capacitance cannot be negative. The discussion revolves around clarifying the implications of these calculations and whether the conclusions drawn are accurate. The inquiry seeks validation of the approach and understanding of the system's characteristics.
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Hello, I am stuck with this one. Your help/comments would be most appreciated.

A charge "+Q" lies at a distance "d" above an infinitely large conducting plane. Applying the method of images, i found the right result that the total charge of the infinite plane is "-Q" and that the stored electric energy is:
W_{E}=-\frac{Q^{2}}{8\pi\epsilon_{0}d}
Since the stored electrostatic energy also satisfies:
W_{E}=CV^{2}/2

it seems that the capacitance of the system would be negative which must be non sense. Therefore the charge above the plane is *not* a capacitor.

Is this correct or am i missing something?
Thanks for your help
 
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