The heat loss (in W) from the fin is

Question

A fin has 5mm diameter and 100mm long. The thermal conductivity of fin material is 400W/mK. One end of the fin is maintained at 130⁰C and its remaining surface is exposed to ambient air at 30C. If the convective heat transfer coefficient is 40W/m²K, the convective heat transfer coefficient is 40W/m²K, the heat loss (in W) from the fin is                      

      (a) 0.08                                                               (b) 5.0

      (c) 7.0                                                                 (d) 7.8