One end of a rod, 35 mm in diameter, is diped into a furnace with the other end projecting in the outer air. After the steady state is obtained, the temperature of the rod is evaluated at two points 180 mm apart and found to be 180 ºC and 145 ºC. The atmospheric air temperature is 25 ºC. If the heat transfer coefficient is 65W/m2 ºC, determine the thermal conductivity of the rod.