A fixed mass of gas is subjected to transformation of states from A to B to C to D and back to A as shown in figure
The succeeding operation that enables this transformation of states are:
Heating, cooling, cooling, heating
P∝T (at constant V); V∝T (at constant P)
A to B - V increases - heating
B to C - P decreases - cooling
C to D - V decreases - cooling
D to A - P increases - heating