Final answer:
Heat exchangers are devices that transfer heat between two places, which is true. They include heat engines that use heat to do work and heat pumps that move heat from cool to warm areas by doing work.
Step-by-step explanation:
Heat exchangers are indeed devices used to transfer heat from one place to another, so the answer is a) True. They can be used in various applications, including industrial processes, refrigeration, and air conditioning systems. Heat engines, for example, are a type of heat exchanger that do work by using part of the heat transfer from a source, denoted as Qh. The work done by these engines (W) utilizes the temperature difference between the hot reservoir (Th) and the cold reservoir (Tc). In contrast, heat pumps use work to move energy from a colder environment to a warmer one, effectively reversing the natural heat flow in accordance with the second law of thermodynamics. Heat pumps, air conditioners, and refrigerators are examples of systems that transfer energy as heat from low to high temperatures, which involves work input to facilitate the transfer.