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The emissivity and the absorptivity of a real surface are equal for radiation with identical temperature and wavelength. This law is referred to as

The emissivity and the absorptivity of a real surface are equal for radiation with identical temperature and wavelength. This law is referred to as Correct Answer Kirchhoff’s law

Emissivity and absorptivity are related by Kirchhoff’s law.

Related Questions

Consider an enclosure formed by three surfaces having the following values of shape factors, emissivities and temperatures Surface 1 i.e. curved cylindrical has an emissivity 0.75 and temperature 800 K Surface 2 i.e. closing disc has an emissivity 0.8 and temperature 700 K Surface 3 i.e. closing disc has an emissivity 0.8 and temperature 700 K The closing flat discs are 25 mm in diameter and they have interspacing distance equal to 100 mm. If the shape factor between these two identical discs is 0.05, calculate the net rate of radiant heat flow from the curve surface to each of the closing end surface
Two large parallel planes with emissivity 0.4 are maintained at different temperatures and exchange heat only by radiation. What percentage change in net radiative heat transfer would occur if two equally large radiation shields with surface emissivity 0.04 are introduced in parallel to the plates?
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The monochromatic emissivity € of a diffuse surface at 1600 K varies with wavelength in the following manner € = 0.4 for 0 < λ < 2 = 0.8 for 2 < λ < 5 Determine the total emissivity
All the forms of matter except gases emit electromagnetic radiation continuously. The gases which electrically or thermally excited emit a certain wavelength only, then which of the following is/are true about the process (i) The spacing between the atoms in the other forms of matter is high than in gas (ii) The spacing between the atoms in gases is high than the other forms of matter (iii) The energy of the emitted radiation depends on the spacing between the atoms (iv) The wavelength of the emitted radiation depends on the spacing between the atoms