(a) A Carnot engine operates between a hot reservoir at 322 K and a cold reservoir at 258 K. If it absorbs 568 J of heat per cycle at the hot reservoir, we have to find the work per cycle that it delivers. (b)We have to calculate the work per cycle that must be supplied for transferring 1230 J of heat from the cold reservoir, if the same engine, by working in reverse, functions as a refrigerator between the same two reservoirs.
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Solution: Click For PDF Version From the data given in the statement of the problem, we note that
For a Carnot engine, we have
Heat absorbed
by the engine per cycle at the hot-reservoir
Therefore, the work per cycle that the engine delivers, W, will be
(b)
For answering
the second part of the problem, when the same Carnot engine works
between the reservoirs in reverse that is it functions as a
refrigerator, we use the result that the heat released to the
hot-reservoir
In the engine working as a refrigerator W is the work done on the engine per cycle. If the amount of heat that is to be transferred per cycle the amount of work that must be supplied to the refrigerator per cycle will be
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