The existence of a thick constant film between two phases is a proposal by which of the following theories?
(a) Film theory
(b) Penetration theory
(c) Surface renewal theory
(d) All of the mentioned
I have been asked this question in semester exam.
The doubt is from Unit Operations topic in division Heat Transfer Equipment, Microwave Heating, Evaporation, Diffusion and Mass Transfer and Dehydration of Food Engineering