Draw the P-T and V-T diagrams for an isothermal process, corresponding to one mole of an ideal gas at an initial pressure and volume `P_(0) and V_(0)` respectively, expanding to a volume `2V_(0)`.

Explanation

The temperature T during the process is, evidently, given by `T=(P_(0)V_(0))/R` (for one mole)
Also, for an isothermal process PV=constant
` :. P_(0)V_(0)=P_(2)(2V_(0)) or P_(2)=P_(0)/2`
(a) The P-T graph is a straight line parallel to the presure axis, with pressure decreasing from `P_(0) " to " P_(0)//2` as shown in figure.

(b) The V-T graph is also a straight line parallel to the volume axis, with volume increasing from `V_(0) "to" 2V_(0)` as shown in figure.