Q. A metal ball of surface area $200 \, \text{cm}^{2}$ , 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 $\left(\sigma = 5.67 \times \left(10\right)^{- 8} \, \text{W } \left(\text{m}\right)^{- 2} \, \left(\text{K}\right)^{- 4}\right)$
NTA AbhyasNTA Abhyas 2020
Solution: