Net flux through a closed sphere

AI Thread Summary
The net electrical flux through a closed sphere in a uniform electric field is zero because there is no charge enclosed within the sphere. This can be mathematically demonstrated using the first half of Gauss's Law, which states that the total electric flux through a closed surface is proportional to the charge enclosed. By visualizing the sphere with an axis aligned to the electric field and integrating the flux over area elements, particularly in a hemisphere, one can show that the contributions cancel out. The discussion confirms that this proof can be accomplished using single-variable calculus. Thus, the net flux through the closed sphere is indeed zero.
PeteyCoco
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Find the net electrical flux through a closed sphere of radius R in a uniform electric field

I know that the flux is going to be 0 since there is no charge enclosed, but how would I show this mathematically? The next half of the question asks about a cylinder with sides parallel to the electric field, which I can prove is 0 easily, but I'm not sure if I know the math to prove the first scenario. Can the sphere-problem be proven with only knowledge of Single-Variable calc?

EDIT: I guess I'm asking if this can be proven easily using the first half of Gauss's Law, ignoring (Q-internal)/(epsilon-nought)
 
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Yes, it can be done with a single-variable integral.

You can visualize that the sphere has an "axis" aligned with the electric field. For area elements, take rings that are centered on that axis, something like this:
images?q=tbn:ANd9GcScKzbiYeomeocc55pBJpWhmYUKtXiqEEj4w3nIbxwtelBZndR1.png
Integrate the flux over all the area elements in a hemisphere, and you'll get that hemisphere's contribution to the total flux.

Hope that's clear enough.
 
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