A smooth, polished platinum surface emits radiation with an emissive power of M = 1.64 kW/m 2 . Using the simplified electromagnetic theory determine its temperature T, the hemispherical total...

A smooth, polished platinum surface emits radiation with an emissive power of M = 1.64 kW/m². Using the simplified electromagnetic theory determine its temperature T, the hemispherical total emissivity ε and the total emissivity ε n in the direction of the surface normal. The specific electrical resistance of platinum may be calculated according to

re = (0.384 6 (T/K) − 6.94) 10⁻⁷
Ωcm .