Question 148Refrigeration & AC - QMED
70% to passRegarding heat transfer principles, which of the following are true?
AHeat transfer always flows from cold regions to hot regions.
BA gas can transfer heat more efficiently than a liquid.
CSteel pipe can transfer heat more efficiently than copper pipe.
DHeat transfer always flows from hot regions to cold regions.
AI Explanation
The correct answer is D) Heat transfer always flows from hot regions to cold regions. This is correct because the second law of thermodynamics states that heat naturally flows from hot regions to cold regions, and not the other way around. Heat will always spontaneously flow from a hotter object to a cooler object, never the reverse, unless external work is done to force the heat to flow in the opposite direction. The other options are incorrect because A) heat does not always flow from cold to hot, B) gases can sometimes transfer heat less efficiently than liquids, and C) the material of the pipe does not determine the direction of heat transfer, only the efficiency.
Related Questions
Q65:In addition to the indicated gauge pressure, what other information is presented... Q77:An increasing head pressure in a refrigeration system, without any corresponding... Q134:The safety heads of most large reciprocating compressors used in refrigeration s... Q108:If an abnormally large difference is maintained between the evaporator refrigera... Q111:If a refrigeration system were short of refrigerant, besides an elevated box tem...
Ready to test your knowledge?
Take a Refrigeration & AC - QMED Practice ExamOfficial Resources