Final answer:
An isobaric process is a thermodynamic process where pressure remains constant, typically involving work being done as the system expands. An isochoric process, however, maintains constant volume and no work is done by the system. The greater work per cycle between an isothermal and an adiabatic process is determined by the larger area enclosed on a PV diagram.
Step-by-step explanation:
An isobaric process is a thermodynamic process in which the pressure of the system remains constant. Specifically, in the context of a thermodynamic cycle, the first step is described as an isobaric process with increasing volume, indicating work is done by the gas as it expands. Table 15.2 Summary of Simple Thermodynamic Processes indicates that during an isobaric process the work done (W) is equal to the pressure (P) multiplied by the change in volume (ΔV).
In contrast, an isochoric process involves maintaining a constant volume where the work done is zero, as volume doesn't change. With regards to the reversible processes discussed, an adiabatic process is when no heat is transferred to or from the system, and it can be reversible if it occurs quasi-statically without any dissipative forces like friction. An isothermal process could also be reversible if it similarly follows a quasi-static path with no entropy generation.
The last step of the cycle in question could either be an isothermal process, where the temperature remains constant, or an adiabatic process, which will not involve transfer of heat. As for the graph two possible paths can be sketched on a PV diagram, one for the isothermal and one for the adiabatic change. The one with greater work per cycle can be determined by the area enclosed by the cycle path on the PV diagram.