12.44: A monatomic ideal gas is the wo
r,tk3jk m3foy:fd; -g rking substance for a refrigerator that undergoes the cyclic process (ABCDA) shown in the PV diagram. The processes are all
f3-3mk rtd,oj f kg:;yisochoric or isobaric with pressures between $P_0$ and $2P_0$ and volumes between $V_0$ and 2$V_0$ . What is the coefficient of performance for this refrigerator?