12.44: A monatomic ideal gas is the working substance for a
d9rl0cgx;7opl 2rh( qrefrigerator that undergoes the cyclic process (ABCDA) shown in the PV diagram. The processes are all isochoric
qhxg20l(l9rdr; oc7por 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?