# Resistance of Various Shapes

1. Feb 24, 2008

### nrhk

How would I find the resistance of said circle

Thickness .15 mm

Last edited: Feb 24, 2008
2. Feb 24, 2008

### cepheid

Staff Emeritus
Are you talking about a hollow cylinder? Are you talking about electrical resistance? If so, don't you need to know the resistivity of the material as well?

Last edited: Feb 24, 2008
3. Feb 24, 2008

### nrhk

Just in terms of variables, yea I guess you could call it a hollow cylinder

I am talking about electrical resistance.

4. Feb 24, 2008

### ZapperZ

Staff Emeritus
What cepheid is trying to tell you is that you need to know the resistivity of the material. Using that information, and the cross-sectional area of your material that is perpendicular to the direction of current flow, will tell you the resistance.

Zz.

5. Feb 24, 2008

### nrhk

I'm solving the problem in terms of variables

I have a circular resistor made out of conducting paper that has inner radius a and outer radius 4a.

I'm pretty sure I have to add an infinite number of circular shells together to get the total resistance of the object.

6. Feb 24, 2008

### ZapperZ

Staff Emeritus
Is this a school work? If it is, it belongs in another forum, and you are usually required to give the full problem first, not your interpretation of the problem. People who are willing to help you with this usually like to see the WHOLE thing first, rather than being given bits and pieces of the problem.

If it isn't, then your geometry is vague.

Zz.