Question

The temperature of a perfect black body is ${727}^{\circ }C$ and its area is $0.1m^2$. If stefan's constant is $5.67\times {10}^{-8}W/m^2{K}^4$, then heat radiated by it (in $J$) in $0.3$ minutes is:

• A. $1701$
• B. $17010$
• C. $102060$
• D. $102.60$

Answer 1

The correct option is C $102060$

The rate of heat flow through the body is given by stephan's boltzman law as,

$\frac{dQ}{dt}=\sigma A{T}^4=5.67\times {10}^{-8}\times 0.1\times {(727+273)}^4=5670W$

Hence, heat radiated in 0.3 minutes is

$Q=5670\times 0.3\times 60=102060J$