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Physics - Heat & Thermo Question with Solution | TestHub

PhysicsHeat & ThermoHeat TransferMedium2 min

PhysicsMediumnumerical

A body which has a surface area 5.0 cm² and a temperature 727°C radiates 300 J of energy each minute. What is its emissivity? Stefan constant = $5.67 \times 1 0^{- 8}$ W/m² K⁴.

Answer:

0.18

Solution:

$P = \frac{300}{60} = 5$ W. $e = \frac{P}{σ A T ^{4}} = \frac{5}{5.67 \times 1 0 ^{- 8} \times 5 \times 1 0 ^{- 4} \times 1 0 ^{12}} = 0.176$ ( $T = 1000$ K).

Subject:PhysicsTopic:Heat & ThermoSubtopic:Heat Transfer

⏱ 2m

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