The initial state of a certain gas is `(P_i,V_i,T_i)`. It undergoes expansion till its volume becomes `V_f` 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 ?

Explanation

The situation is shown in the given P `to` V graph where variation is shown for each process.

Process 1 is isobaric and process 2 is isothermal. Since work done is equal to the area under the P`to` V curve, here area under the P `to` V curve 1 is more, so work done is more in isobaric process.