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Thermal radiation law: fill in Stefan–Boltzmann law wording Complete the statement: The total radiation from a black body per second per unit area is __________ the fourth power of its absolute temperature. Choose the correct phrase.

Difficulty: Easy

equal to
proportional to
inversely proportional to
independent of

Correct Answer: proportional to

Explanation:

Concept/Approach
Stefan–Boltzmann law: E = σT⁴ for a black body, where σ is the Stefan–Boltzmann constant.

Interpretation
The phrasing is that emissive power is proportional to the fourth power of absolute temperature (with σ as the constant of proportionality).

Final Answer
proportional to

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