Capacitance of a cylinder containing an infinite number of cylinders

AI Thread Summary
The discussion centers on calculating the capacitance of a finite cylinder containing an infinite number of infinitely thin cylinders. The definition of capacitance as the ratio of charge to voltage is emphasized, raising questions about the meaning of capacitance in this context. Clarifications are sought regarding the configuration of the outer cylinder, specifically whether it is open or closed at the ends. It is suggested that if the outer cylinder is fully closed, the capacitance would not depend on the inner cylinders. The conversation highlights the complexity of the problem, particularly with the implications of having infinitely thin cylinders and their arrangement.
IanS
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I am a struggling physiology PhD student and would very much appreciate some help...

I need an expression for the capacitance of a cylinder (of finite radius and length) containing an infinite number of infinitely thin cylinders.

Any help would be greatly appreciated!

Many thanks,
-Ian
 
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Your question is poorly posed. Capacitance is defined as the ratio of the charges on two conductors (+Q on one and -Q on the other) to the voltage (V) between them,
so C=Q/V. With an infinite number, what do you mean by capacitance?
Is the outer cylinder of finite length open or closed at the ends?
 
Is the outside cylinder fully closed (that is, closed off at both ends)? If it is, then it does not matter what is inside it (I'm 90% sure of that, but someone correct me please).
Is there any separation between the outside cylinder and the inner ones? If not, then it would be identical to a solid cylinder, which would be identical (in capacitance) to a cylindrical shell.

Otherwise, the problem implies an infinitessimal distance between layers of a capacitor, which implies a capacitance that approaches infinity.
 
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