Thermodynamics SECOND LAW OF THERMODYNAMICSThis cycle is known as a Carnot Cycle. The heat input (Q_{H}) in a Carnot Cycle is graphicallyrepresented on Figure 21 as the area under line 2-3. The heat rejected (Q_{C}) is graphicallyrepresented as the area under line 1-4. The difference between the heat added and the heatrejected is the net work (sum of all work processes), which is represented as the area of rectangle1-2-3-4.Figure 21 Carnot Cycle RepresentationThe efficiency (h) of the cycle is the ratio of the net work of the cycle to the heat input to thecycle. This ratio can be expressed by the following equation.h= (Q_{H} - Q_{C})/Q_{H} = (T_{H} - T_{C})/T_{H}= 1 - (T_{C}/T_{H}) (1-23)where:h= cycle efficiencyT_{C}= designates the low-temperature reservoir (°R)T_{H}= designates the high-temperature reservoir (°R)Rev. 0 Page 73 HT-01