A hot body will radiate heat most rapidly, if its surface is___________________?
Correct answer: B. Black & rough
- A. White & rough
- B. Black & rough
- C. White & polished
- D. Black & polished
Explanation
Radiation is greatest from a surface with high emissivity, and black, rough surfaces have much higher emissivity than white or polished surfaces. Polished surfaces are generally good reflectors and poor emitters.
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