Example

Sketch a PV diagram of the following processes:

(I)   A gas is compressed at constant pressure Pi from volume Vi to volume Vf. It is then kept at constant volume while the pressure is increased to Pf.

(II)  A gas is increased in pressure from Pi to Pf while its volume is held constant at Vi. It is then compressed at constant pressure to a final volume Vf.

In which process is more work done on the gas? Why?