Physics - Heat & Thermo Question with Solution | TestHub

1 to 2 is isochoric heating: $P$ rises and $Q=n{C}_v\Delta T>0$. 2 to 3 is isothermal expansion: $Q=W>0$. 3 to 1 is a line through the origin, so $V\propto T$ and $P$ is constant: isobaric cooling and compression with $Q=n{C}_p\Delta T<0$. On a $P$-$V$ diagram the cycle runs clockwise, so net work is positive and D is wrong.