Graphically show the total work done in an expansion when the state of an ideal gas is changed reversibley and isothermally from( P_(i), V_(i))to(P_(f),V_(f)) . With the help ofa PV plot,compare the work done in the above case with carried out against a constant external pressure P_(f).

Graphically show the total work done in an expansion when the state of

1.	Graphically show the total work done in an expansion when the state of an ideal gas is changed reversibley and isothermally from( P_(i), V_(i))to(P_(f),V_(f)) . With the help ofa PV plot,compare the work done in the above case with carried out against a constant external pressure P_(f).
Answer» Solution : (i) Area AB `V_(i) V_(f)` represets total work done for REVERSIBLE isothermal EXPANSION from `(P_(i), V_(i)) ` to `(P_(f),V_(f))` (ii) Area CB `V_(i)V_(f)` represents work done against constant PRESSURE`P_(f)` OBVIOUSLY , work (i) `GT` work (ii)