As shown in the figure below, two reversible cycles arranged in series each produce the same net work, Weycle: The first cycle receives energy QH by heat transfer from a hot reservoir at TH = 1000°R and rejects energy Q by heat transfer to a reservoir at an intermediate temperature, T. The second cycle receives energy Q by heat transfer from the reservoir at temperature Tand rejects energy Qc by heat transfer to a reservoir at Tc = 450°R. All energy transfers are positive in the directions of the arrows. Hot reservoir at TH R1 W cycle Reservoir vQ at T R2 W cycle Cold reservoir at Tc Determine: (a) the intermediate temperature T, in °R, and the thermal efficiency for each of the two power cycles. (b) the thermal efficiency of a single reversible power cycle operating between hot and cold reservoirs at 1000°R and 450°R, respectively. Also, determine the ratio of the net work developed by the single cycle to the net work developed by each of the two cycles, Wcycle-

4. What is the second law of thermodynamics, give its Clausius and Kelvin-Planck statements and justify on their basis why a perpetual motion machines that extracts heat from ambient environment to do work is not feasible. What is difference between reversible and an internally reversible process, and why are most actual processes considered irreversible. Numerical:

A system consisting of a gas contained in a cylinder with a frictionless piston is taken around the closed path a→b→c→a where the process c→a is isothermal. During the closed cycle, the system expels 150 J to the environment. If the work done on the system during the isobaric leg b→c of the cycle is 250 J, what is the heat expelled/absorbed by the gas in the isothermal leg c→a in J.

Shown below is P-V diagram for a reversible cycle enclosed by 4 reversible process curves.  The curve 1-2 and the curve 3-4 are  reversible isothermal processes, and the curve 2-3 and the curve 1-4 are reversible adiabatic processes. If the cycle direction is counter clockwise, answer the question below. Select curve(s) which represent process(es) having heat interactions?____       A. curve 1-2     B. curve 2-3   C. curve 1-4   D. curve 3-4