Calculate rate of heat radiated per unit area from the surface of a fu

1.	Calculate rate of heat radiated per unit area from the surface of a furnace at a temperature 2000K, assuming it to be a black body. If the emissivity is 0.37, then what Is the amount of heat radiated per second? G = 5.67 ×10-8Wm-2K-4 .
Answer» From Stefan’s law of radiation, the amount of heat radiated per second is E = σT⁴. E = 5.67 × 10^-8 × (2000)⁴ = 5.67 × 2⁴ × 10⁴ = 5.67 × 16 × 10⁴ = 9.072 × 10⁵Js^-1. If e is the emissivity of the surface, then the heat radiated per second R¹ = eR = 0.37 × 9.072 × 10⁵ = 3.35 × 10⁵ Js^-1.

Calculate rate of heat radiated per unit area from the surface of a furnace at a temperature 2000K, assuming it to be a black body. If the emissivity is 0.37, then what Is the amount of heat radiated per second? G = 5.67 ×10-8Wm-2K-4 .

Answer»

From Stefan’s law of radiation, the amount of heat radiated per second is E = σT⁴.

E = 5.67 × 10^-8 × (2000)⁴

= 5.67 × 2⁴ × 10⁴

= 5.67 × 16 × 10⁴

= 9.072 × 10⁵Js^-1.

If e is the emissivity of the surface, then the heat radiated per second R¹ = eR

= 0.37 × 9.072 × 10⁵

= 3.35 × 10⁵ Js^-1.