A 2-cm-OD bare aluminum electric power transmission line with an emissivity of 0.07 carries 500 amps at

Question:

A 2-cm-OD bare aluminum electric power transmission line with an emissivity of 0.07 carries 500 amps at 400 kV. The wire has an electrical resistivity of 1.72 micro-ohms cm2/cm at 20?C and is suspended horizontally between two towers separated by 1 km. Determine the surface temperature of the transmission line if the air temperature is 20?C. What fraction of the dissipated power is due to radiation heat transfer?GIVENAn aluminium electric power transmission line suspended horizontallyEmissivity (ε) in air = 0.3Line diameter (D) = 2 cm = 0.02 mCurrent (I) = 500 ampVoltage (V) = 400 kVElectrical resistivity (ρe) = 1.72 x cm2/cm at 20?CSpace between towers (L) = 1 kmAir temperature (T??) = 20?C = 293 KASSUMPTIONSSteady stateThe wire radiates to the surroundings which behave as a black body enclosure atT??