Physics - Heat & Thermo Question with Solution | TestHub

Consider paths from A to B.

$$\Delta U_2=\Delta U_1$$

$$W_2>W_1$$

$$Q_2>Q_1$$

$$\Rightarrow Since{Q}_1=0,then{Q}_2>0$$

Take the gas from $A\to B$ along a straight line and back $B\to A$ along a curve:

$$\Delta U=0$$

$$Q_{cycle}=W_{cycle}$$

$$Q_{AB}+0=W_{cycle}(shadedarea)$$

Consider the following cyclic process 1, 2, 3. For this cyclic process, $Q_{net}=-ve$.

$$Q_2>0$$

$$Q_3=0$$

$$Q_1+Q_2+Q_3<0$$

$$Q_1<0$$