An ideal engine may be thought of as a device operating in reversible cycles between two heat reservoirs, one at a higher temperature than the other. In each cycle, the engine takes a certain amount of heat from the higher temperature reservoir R1. A fraction of this energy is used by the engine to do work, while the rest of the energy is transferred to the lower temperature reservoir R2.
Which statement pertaining to entropy is true?
A) The entropy of the reservoir R1 increases.
B) The entropy of the reservoir R2 increases.
C) The entropy of the engine increases after each complete cycle.
D) The entropy of the engine decreases after each complete cycle.

Steam is generated in a boiler of a cogeneration plant at 10 mpa and 450°c at a steady rate of 5 kg/s. in normal operation, steam expands in a turbine to a pressure of 0.5 mpa and is then routed to the process heater, where it supplies the process heat. steam leaves the process heater as a saturated liquid and is pumped to the boiler pressure. in this mode, no steam passes through a condenser, which operates at 20 kpa. (a) determine the power produced in the turbine and the rate at which process heat is supplied in this mode. (b) determine the power produced in the turbine and the rate of process heat supplied if only 60 percent of the steam is routed to the process heater and the remainder is expanded to the condenser pressure. (3.32 mw; 9.69 mw; 4.25 mw; 5.82 mw)