Determine the power requirement of a soldering iron in which the tip is maintained at 400?C. The tip is a cylinder 3 mm in diameter and 10 mm long. Surrounding air temperature is 20?C and the average convective heat transfer coefficient over the tip is 20 W/(m2 K). Initially, the tip is highly polished giving it a very low emittance.GIVENSoldering iron tipDiameter (D) = 3 mm = 0.003 mLength (D) = 10 mm = 0.01 mTemperature of the tip (Tt) = 400?CTemperature of the surrounding air (T??) = 20?CAverage convective heat transfer coefficient ( hc ) = 20 W/(m2 K)Emittance is very low (ε = 0)ASSUMPTIONSSteady state conditions existAll power used by the soldering iron is used to heat the tipRadiative heat transfer from the tip is negligible due to the low emittanceThe end of the tip is flatThe tip is at a uniformtemperature

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T--20°C D= 0.003 m T= 400°C L= 0.01 m Soldering Iron