Other Charge Distributions - Fields & Potentials

Hannah Baker
8 min read
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Study Guide Overview
This study guide covers advanced applications of charge distributions, Gauss' Law, and electric potential. It examines extended charge distributions (lines, rings, sheets) and how to calculate their electric fields and potentials using integration. It reviews applying Gauss' Law to various shapes like spheres, cylinders, and sheets to determine electric fields. Finally, it discusses calculating potential differences for various charge configurations, including lines and conducting sheets.
#Advanced Applications of Charge Distributions, Gauss' Law, and Electric Potential
This section dives into more complex scenarios involving charge distributions, Gauss' Law, and electric potential calculations. It builds upon the foundational concepts covered earlier, so make sure you're comfortable with those before proceeding. Let's get started! 🚀
#Extended Charge Distributions
So far, we've treated charged objects as point charges. Now, we'll tackle situations where charge is spread out over a line, ring, or sheet. The key idea is to break down the total charge Q into tiny pieces dq, each contributing a small electric field dE. Then, we integrate to find the total field E. Here's the general formula:
where r is the radius vector.
#Ring of Charge Example



If x >>> a, the equation simplifies to that of a point charge, which is a great way to check your work.
#Line of Charge Example

First, express dq in terms of dy using the linear charge density λ:

Then, integrate to find the total electric field, using the Pythagorean theorem to find r:

Remember that the key to solving these problems is to break the charge distribution into small pieces (dq), find the field due to each piece (dE), and then integrate to find the total field.
#Gauss' Law for Various Shapes
Gauss' Law is your best friend for finding electric fields due to symmetrical charge distributions. Here's a quick rundown of how to apply it to different...

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