A cyclic process ABCA is shown in the V-T diagram. Process on the P-V diagram is : 

1. From the given V-T diagram, we can see that in process AB, v \(\propto\) T. Therefore pressure is constant (as quantity of the gas remains same).
2. In process BC, V = constant and in process CA, T = constant.
3. Therefore, these processes are correctly represented on P-V diagram by graph (3).