A thermal system is constructed from a composite wall as shown in Fig.1. Assume that the heat transfer is one dimensional steady-state and the thermal properties of each layer remain

constant. (a) Draw the thermal resistance network of the system shown in Fig.1. (b) Calculate the rate of heat transfer Q through the system shown in Fig.1. Assume that; k_{A}=150 \frac{\mathrm{W}}{\mathrm{m}^{\circ} \mathrm{C}}, k_{B}=30 \frac{\mathrm{W}}{\mathrm{m}^{\circ} \mathrm{C}}, k_{C}=65 \frac{\mathrm{W}}{\mathrm{m}^{\circ} \mathrm{C}}, k_{D}=50 \frac{\mathrm{W}}{\mathrm{m}^{\circ} \mathrm{C}} (c) Is the rate of heat transfer Q through each layer constant? Justify your answer. (d) Draw a schematic diagram to show the temperature distribution through the wall D and calculate the temperature at the middle of the wall D (i.e. at wall thickness= x/2cm). [Based on your last two digits of your ID, each student should choose his/her own value of x from Table-1].