A metal ball of surface area 200 cm 2 , temperature 527 o C is surrounded by a vessel at 27 o C . If the emissivity of metal is 0.4 , then the rate of loss of heat is nearly σ = 5.67 × 10 - 8 W m - 2 K - 4

Step-by-step solution

Rate of heat loss per unit time per unit area = e σ A T 4 - T 0 4 = 0.4 × 5.67 × 10 - 8 × 200 × 10 - 4 × 800 4 - 300 4 = 5.67 × 0.4 × 2 × 10 - 8 + 2 - 4 × 10 8 64 2 - 9 2 = 5.67 × 0.8 × 10 - 2 55 × 73 = 18212.04 × 10 - 2 = 182.12 W