Since A and B lie on an isotherm, we have TA = TB = T0; thus, the internal energies at A and B are same. For an isothermal process AB, we have W = hRTln(
V2
V1
) = RT0ln(4) = P0V0ln(4)
Here, the path CA is due to the isochoric process, that is, VC = VA = V0 Therefore,