An electrical generating plant operates at a boiler temperature of 200$\degree$C and exhausts the unused heat into a nearby river at 20$\degree$C. What is the maximum theoretical efficiency of the plant? (0$\degree$C = 273 K)

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Quizplus · Accepted Answer

The maximum theoretical efficiency of a heat engine is given by the Carnot efficiency: 1 - (Tc/Th), where Tc is the cold reservoir temperature and Th is the hot reservoir temperature, both in Kelvin. Converting the given temperatures to Kelvin: Th = 200 + 273 = 473 K, Tc = 20 + 273 = 293 K. The efficiency is 1 - (293/473) = 0.380, or 38%.

An Electrical Generating Plant Operates at a Boiler Temperature of 200