Question

Number 14

data points in the temperature range 300 K to 3000 K. 1.14 Calculate the thermal radiation emitted by a sur- face with an emissivity of 0.8 and a temperature of 1300℃. Din 1.20 1.21

Answer 1

Thermal radiation is given as;

$q=\epsilon \sigma T^4$

here,

$\epsilon = emissivity$

$\sigma = Stefan-Boltzmann\;\;constant=5.67\times10^{-8}\;\;W/m^2K^4$

$T=temperature\;\;(in\;\;Kelvin)$

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Given,

$T = 1300^{\circ}C=(1300+273.15)\;\;K=1573.15\;\;K$

$\epsilon = 0.8$

Hence,

$q=\epsilon \sigma T^4$

$\Rightarrow q=(0.8) (5.67\times10^{-8}\;\;W/m^2K^4) (1573.15\;\;K)^4$

$\Rightarrow q=277813.6\;\;W/m^2$

$\Rightarrow q=2.778\times 10^5\;\;W/m^2$