posted by Rafeeq .
A fin 30 cm long & 10mm diameters throughout is made of steel alloy of thermal conductivity 43 W/m-deg. the fin attached to a plane heated wall at 200 deg.C temp. extends into surroundings at 25 deg.C.& Unit surface conductance of 120W/m^2-deg. Workout the heat flow rate from the fin to surroundings.Presume that the tip of the fin is insulated & thermal radiation effects are negligible.