Question

Two thin metallic spherical shells of radii r₁ and r₂ (r₁ < r₂) are placed with their centres coinciding. A material of thermal conductivity K is filled in the space between the shells. The inner shell is maintained at temperature θ₁ and the outer shell at temperature θ₂(θ₁ < θ₂). The rate at which heat flows radially through the material is :-

Answer 1

Correct answer is 1.

Thermal resistance of spherical sheet of thickness dr and radius r is