8. An annular fin of rectangular profile is attached to a circular tube having an outside diameter of 25 mm and a surface temperature of 250 °C. The fin is 1 mm thick and 10 mm long and the temperature and the convection coefficient associated with the adjoining fluid are 25 °C and 25 W/m2.K, respectively. The thermal conductivity of the fin material may be assumed to be 240 W/m.ºC. If fins are spaced at 5-mm increments; Determine the increase in heat transfer from the tube per 5mm of its length as a result of adding only one fin? 5mm Ть T-250°C- Aluminum t=1mm L-10 mm- 1-12.5mm T-25 °C h25 W/m²K