Thermodynamics (Physics)

As shown in the figure, five Carnot engines, each with efficiency and same number of cycles per unit time, are operating between six heat reservoirs. The amount of heat released per cycle by one engine is completely absorbed by the next engine. Consider Q0 to be the amount of heat absorbed per cycle by the first engine and W as the amount of total work done by all the engines per cycle, then the net efficiency of the system is found to be net = WQ0 = 211243. The value of is: [figure]

An ideal monatomic gas of n moles is taken through a cycle WXYZW consisting of consecutive adiabatic and isobaric quasi-static processes, as shown in the schematic V-T diagram. The volume of the gas at W, X and Y points are, 64 cm3, 125 cm3 and 250 cm3, respectively. If the absolute temperature of the gas TW at the point W is such that nRTW=1 J (R is the universal gas constant), then the amount of heat absorbed (in J) by the gas along the path XY is [figure]