If the boundary of system moves by an infinitiesimal amount, the work involved is given by dw= -P_("ext") dV, for irreversible process W= -P_("ext") Delta V (where DeltaV= V_(f)- V_(i)). For reversible process P_("ext") = P_("int") +- dP ~~ P_("int"), so for reversible isothermal process W= -nRTln (V_(f))/(V_(i)). 2 mole of an ideal gas undergoes isothermal compression along three different paths: (i) reversible compression from P_(i)= 2 bar and V_(i)= 8 to P_(f)=20 bar (ii) a single stage compression against a constant external pressure of 20 bar (iii) a two stage compression consisting initially of compression against a constant external pressure of 10 bar until P_("gas") = P_("ext"), followed by compression against a constant pressure of 20 bar until P_("gas") = P_("ext"). Total work done on the gas in two stage compression is

If the boundary of system moves by an infinitiesimal amount, the work

1.	If the boundary of system moves by an infinitiesimal amount, the work involved is given by dw= -P_("ext") dV, for irreversible process W= -P_("ext") Delta V (where DeltaV= V_(f)- V_(i)). For reversible process P_("ext") = P_("int") +- dP ~~ P_("int"), so for reversible isothermal process W= -nRTln (V_(f))/(V_(i)). 2 mole of an ideal gas undergoes isothermal compression along three different paths: (i) reversible compression from P_(i)= 2 bar and V_(i)= 8 to P_(f)=20 bar (ii) a single stage compression against a constant external pressure of 20 bar (iii) a two stage compression consisting initially of compression against a constant external pressure of 10 bar until P_("gas") = P_("ext"), followed by compression against a constant pressure of 20 bar until P_("gas") = P_("ext"). Total work done on the gas in two stage compression is
Answer» 40 80 16 None of these Answer :B