Right

Wrong

two constant volume and two isentropic processes

two constant pressure and two isentropic processes

two constant volume and two isothermal processes

one constant pressure, one constant volume and two isentropic processes

increase in availability of energy

increase in temperature

decrease in pressure

degradation of energy

W_{1 - 2} = 0

Q_{1 - 2} = 0

dU = 0

all of these

23.97 bar

25 bar

26.03 bar

34.81 bar