An ideal monatomic gas expands isobarically, doubling the volume, from a state A to state B. It is then compressed isothermally from state B to state C and finally cooled at constant volume until it returns to state A. No gas is allowed to enter or escape during the any of the processes. a) Draw a PV diagram for this cycle.

b) How many atoms are in the gas?

c) Is the cycle a heat engine or pump?

d) If the cycle is a heat engine, what is the efficiency of the cycle. If the cycle is a heat pump, what is the coefficient of performance?