While the total emissivity of a perfect black body is unity, the same for a real body is__________________?
Correct answer: D. Between 0 and 1
- A. 0
- B. 1
- C. > 1
- D. Between 0 and 1
Explanation
A black body absorbs and emits perfectly, so its emissivity is 1. A real surface emits less than a black body under the same conditions, giving emissivity between 0 and 1.
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