In how many categories heat exchangers are classified on the basis of physical state of heat exchanging fluids? April 4, 2021 by admin Question: In how many categories heat exchangers are classified on the basis of physical state of heat exchanging fluids? A. 1 B. 2 C. 3 D. 4 Answer» b. 2 Note: The above multiple-choice question is for all general and Competitive Exams in India.