Consider steady-state heat conduction across the thickness in a plane wall of thickness 0.6 m. The wall has a normal area 1.5 m2 and is made up of material of thermal couductivity 0.4 W/m°C. There is no generation of thermal energy within the wall. The temperatures on the two sides are 800°C and 300°C. The thermal resistance of the wall is:
1
1.5 W/°C
2
1 W/°C
3
1.5 °C/W
4
1 °C/W