The thermal resistance for heat conduction through a spherical wall is

1.	The thermal resistance for heat conduction through a spherical wall is
A.	(r₂-r₁)/2πkr₁r₂
B.	(r₂-r₁)/3πkr₁r₂
C.	(r₂-r₁)/πkr₁r₂
D.	(r₂-r₁)/4πkr₁r₂
Answer» E.

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The thermal resistance for heat conduction through a spherical wall is

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