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Emissive and absorptive power of a material at 2000 ~K is 8 and 10 respectively, calculate the emissivity of IBB (Ideal black body)

Options

  1. A0.2
  2. B0.4
  3. C0.6
  4. D0.8

Correct answer

D. 0.8

Step-by-step solution

The ratio of emissive power to absorptive power is the same for all surfaces at the same temperature and is equal to the emissivity for a perfectly black body at that temperature. i.e, e a = Here, e=8, a=10 = e a = 8 10 =0.8

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