Deriving Electric Charge: Line, Ring, Cylinder, Cone, Sphere & Shell

AI Thread Summary
The discussion focuses on deriving formulas for electric charge distributions for various geometries without using Gauss's Law. The user has successfully derived formulas for several cases, including infinite and semi-infinite lines of charge, rings, and disks. They seek assistance in setting up integrals for cylinders, cones, spheres, and shells, noting that the ring of charge serves as a foundational element for these derivations. A participant suggests that different coordinate systems are key to the derivations, highlighting the variations in cylindrical and spherical coordinates. The user expresses gratitude and confirms they now have the necessary information to proceed with their work.
Chris W
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Hi all. I need some help.
Without using Gauss's Law, I have to derive the formula for the electric charge for different cases.
-I already did few cases such as:
1. Infinite line of charge
2. Semi - infinite line of charge
3. Ring of charge
4. Semi - Ring of charge or any arc of charge
5. Disk of charge
6. Infinite Sheet of Charge

-I need to derive:
7. Cylinder of charge
8. Cone of charge
9. Sphere of charge
10. Shell of Charge

I know that the basic "building block" for cases 7-10 is the ring of charge which I already have. Basically what I need is the setup of the integral for cases 7-10.

Thank you

Chris W
 
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It's just an exercise in different coordinates. A cylinder has constant r, varying z and phi/theta in cylindrical coordinate, a cone has varying z, r and phi/theta in cylindricalm a sphere has varying, r, phi, theta in spherical and a shell has constant r, varying phi, theta in spherical
 
Thanks!

Yeah. Looks like I have all I need now I just have to set up the integrals.

Thanks! wow that was quick ... lol


please see what I have so far ... I hope all is good!

Thank you one more time

see attachment
 

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  • Infinite line of charge.jpg
    Infinite line of charge.jpg
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  • Semi- infinite line of charge .jpg
    Semi- infinite line of charge .jpg
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  • ring of charge.jpg
    ring of charge.jpg
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this is the rest of what I have so far

sheet of charge can be viewed as the disk of charge and letting the R go to the infinify
 

Attachments

  • disk of charge page 1of2.jpg
    disk of charge page 1of2.jpg
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  • disk of charge page 2of2.jpg
    disk of charge page 2of2.jpg
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  • semi-ring or arc of charge.jpg
    semi-ring or arc of charge.jpg
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