Resistance of a sphere

[eeprom]

This is not a very practical question, but one I have thought about quite a bit. Just curious. If I took a copper sphere and measured the resistance across the sphere, I would get some value of resistance. If I tripled the size of the sphere, how would the resistance change?

EE

 

[stevenal]

So if you triple the radius, you've tripled the length of the current path which would have the effect of tripling the resistance. On the other hand, that same triple radius sphere would have 9 times the average cross sectional area, reducing the resistance by 9X. I would say your triple radius sphere has 1/3 the resistance of the first.

 

[dArsonval]

At what precise points of the sphere, is the sphere being measured?

 

[oldfieldguy]

Solid sphere? Or hollow? If hollow, how thick is the skin?


old field guy

 

[MadMango]

This might be of interest...

https://www.physicsforums.com/threads/electrical-resistance-of-a-sphere.653837/

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of these Forums?

 

[eeprom]

This would be a solid sphere, resistance is measured at opposite points anywhere on the sphere. The distance between measuring points would be one diameter.

I don't know how to prove it, but I believe the resistance would be constant.