Topic: Heat Transfer
What is the net radiant interchange per square meter for two very large plates at temperatures 800 K and 500 K respectively? (The emissivity of the hot and cold plates are 0.8 and 0.6 respectively. Stefan Boltzmann constant is 5.67x10^-8 W/m^2K^4).
- A. 10.26 kW/m²
- B. 102.6 kW/m²
- C. 1.026 kW/m²
- D. 1026 kW/m²
Answer: A. 10.26 kW/m²
Explanation: Net Radiant heat exchange per unit area Q_net/A = sigma*(T1^4 - T2^4) / (1/e1 + 1/e2 - 1). Substituting the values: 5.67x10^-8 * (800^4 - 500^4) / (1/0.8 + 1/0.6 - 1) = 10.26 kW/m².