One of two thin coatings may be applied to a metal plate, yielding the following spectral emissivities above and below a cutoff wavelength of \(\lambda_{c}=8 \mu \mathrm{m}\).

If the plate temperature is \(T_{s}=600 \mathrm{~K}\) and the surroundings is at \(400 \mathrm{~K}\), determine the radiosity and net radiation heat flux at the surface of the plate for no coating, coating A, and coating B. Which coating provides the largest net radiation flux? If the cutoff wavelength were \(\lambda_{c}=6 \mu \mathrm{m}\) rather than \(8 \mu \mathrm{m}\), which coating would provide the largest net radiation flux?

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Coating (8 m) (. > 8 m) A 0.75 0.25 B 0.25 0.75 None 0.25 0.25