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## Homework Statement

Find the Electric Field inside a Charged Sphere (charge only on the surface) and between two Parallel Plates (oppositely charged) separated by some distance d.

## Homework Equations

Gauss' Law: [itex]\oint EdA = \frac{Qencl}{\epsilon}[/itex]

## The Attempt at a Solution

So for the charged sphere, I choose my Gaussian Surface S to be a sphere inside. I see that S encloses no charges, so Qencl = 0. Thus, E = 0.

However, for the parallel plates, I know how to get the answer by finding E of each plate individually and summing them vectorally. The resultant E is NOT 0. I am very confused because if I choose my Gaussian surface S to be a cube or whatever in the space between the parallel plates, S contains no charges. By my logic from the charged sphere, E should equal 0, which is NOT the case.

So basically, can anyone explain to me why I have to sum the E fields from individual plates instead of doing it with my second method?

Thank you very much!