Question

A point source of heat of power $P$ is placed at the center of a spherical shell of mean radius $R$. The material of the shell has thermal conductivity $K$. If the temperature difference between the outer and inner surface of the shell is not to exceed $T$, the thickness of the shell not be less than:

• A. $\frac{4\pi KT{R}^2}{P}$
• B. $\frac{4\pi K^2{T}^2}{P}$
• C. $\frac{4\pi KT{R}^2}{3P}$
• D. $\frac{2\pi KT{R}^2}{3P}$

Answer 1

The correct option is A $\frac{4\pi KT{R}^2}{P}$