An ideal monatomic gas ($\gamma = 5/3$) is taken round the cycle shown in the figure. From state A, at temperature $T_0$, it expands at constant pressure to twice its volume (state B). It then expands adiabatically until its temperature is $T_0$ again (state C). Finally it is compressed at constant temperature back to A. Let $n$ be the number of moles. Which of the following statements are correct?

Fig. 1: A pressure-volume graph of a cycle. From point A at volume V0 a horizontal line runs right to point B at 2V0. A steep falling curve (an adiabat) runs from B down to point C at a much larger volume, and a gentler falling curve (an isotherm) runs from C back up to A. Arrows show the order A, B, C.