An electric furnace is designed to radiate of thermal energy from its inner wall

PHYSICS · Single correct · A Level · Physics · Further mechanics and thermal physics · Further mechanics and thermal physics

Problem

An electric furnace is designed to radiate

2.0\times10^{4}\,\text{W}

of thermal energy from its inner wall, which is maintained at

1.20\times10^{3}\,\text{K}

. The wall material has an emissivity of

0.80

and behaves as a diffuse radiator. What is the minimum total surface area of the wall? (a)

0.17\,\text{m}^{2}

(b)

0.26\,\text{m}^{2}

(c)

0.21\,\text{m}^{2}

(d)

0.14\,\text{m}^{2}