For an ideal gas, reversible isothermal and reversible adiabatic processes are described by the relations PV=constant and PVγ=constant respectively, where γ>1.
a. (i) Starting from the respective relations, obtain an expression for the slope (dVdP) of each curve on a P–V diagram in terms of P and V at an arbitrary point on the curve.
b. (ii) Show that, for the same values of P and V, the magnitude of the slope for the adiabatic curve exceeds that for the isothermal curve by a factor of γ.
c. (iii) Hence explain, with physical reasoning based on the First Law of Thermodynamics, why the adiabatic curve is qualitatively steeper than the isothermal curve throughout the diagram.