Sublimation of a long cylinder made of napthelene occurs in a large volume of stagnant air. The time required for its complete sublimation is
(a) infinite
(b) half the time of sublimation of a sphere of the same mass
(c) twice the time of sublimation of a cylinder of the same mass and lengthy/diameter=1
(d) half the time of sublimation of a cylinder of the same mass and lengthy/diameter=1
The question was asked in exam.
This key question is from Diffusion through Variable Area topic in section Diffusion in Solids and Molecular Diffusion in Fluids of Mass Transfer