Helium gas ( = 1.67) is initially at a pressure of 16 atm, a volume of 1

Helium gas (γ = 1.67) is initially at a pressure of 16 atm, a volume of 1 L, and a temperature of 600 K. It is expanded isothermally until its volume is 4 L and is then compressed at constant pressure until its volume and temperature are such that an adiabatic compression will return the gas to its original state.

(a) Sketch this cycle on a PV diagram.

(b) Find the volume and temperature after the isobaric compression.

(c) Find the work done during each cycle.

(d) Find the efficiency of the cycle.