Question

The rate of dissipation of the heat by a black body at temperature $T$ is $Q.$ What will be the rate of dissipation of heat by another body of the same area at temperature $2T$ and having emissivity $0.025$ ?

• A. $8Q$
• B. $4Q$
• C. $16Q$
• D. $32Q$

Answer 1

The correct option is C $16Q$

$\begin{array}{c}\frac{dQ}{dt}=\sigma eA{T}^{4}ande=1,t,\frac{dQ}{dt}=Q\\ \therefore \frac{dQ}{dt}=0.025\sigma A{\left(2T\right)}^4=0.025\times 16Q=0.48\\ Answershouldbecifemissivitybe0.25instendedof\mathrm{0.025.}\end{array}$