The initial state of a certain gas is (P_(i)V_(i) T_(i)). It undergoes expansion till its volume becomes V_(int).Consider the following two cases. a) The expansion takes place at constant temperature. b) The expansion takes place at constant pressure. Plot the P-V diagram for each case. In which of the two cases, is the work done by the gas more ?

The initial state of a certain gas is (P_(i)V_(i) T_(i)). It undergoes

1.	The initial state of a certain gas is (P_(i)V_(i) T_(i)). It undergoes expansion till its volume becomes V_(int).Consider the following two cases. a) The expansion takes place at constant temperature. b) The expansion takes place at constant pressure. Plot the P-V diagram for each case. In which of the two cases, is the work done by the gas more ?
Answer» Solution :The P-V DIAGRAM for each case is SHOWN in the FIGURE. In case (i) `P_(i)V_(i)=P_(f)V_(f)` : therefore PROCESS is isothermal. Work done = area under the PV curve so work is more when the gas expands at constant pressure.