If one mole of an ideal gas at (P1,V1) is allowed to expand reversibly and isothermally (A to B) its pressure is reduced to one-half of the original pressure (see figure). This is followed by a constant volume cooling till its pressure is reduced to one-fourth of the initial value (B → C). Then it is restored to its initial state by a reversible adiabatic compression (C to A).
The net work done by the gas is equal to:
(1) RT(ln2−2(γ−1)1)
(2) −2(γ−1)RT
(3) 0
(4) RTln2