A very long copper rod 20 mm in diameter extends horizontally from a plane heated wall maintained at 100 degree celsius. The surface of the rod is exposed to an air environment at 20 degree celsius with convective heat transfer coefficient of 8.5 w/m² degree. Calculate the heat loss if the thermal conductivity of copper is 400 w/m degree.
1) 20.71
2) 30.71
3) 40.71
4) 10.71
