Question

Stefan-Boltzmanns Law for a perfect black body is represented by

• A. $\frac{dQ}{dt}=\sigma A{T}^2$
• B. $\frac{dQ}{dt}=\sigma A{T}^3$
• C. $\frac{dQ}{dt}=\sigma A{T}^4$
• D. $Q=\sigma A{T}^4$

Answer 1

The correct option is C $\frac{dQ}{dt}=\sigma A{T}^4$

Stefan boltzmann's law, $\Rightarrow \frac{dQ}{dt}=\sigma A\epsilon T^4$

( for black body, $\epsilon =1$)

So, for black body stefan's boltzmann's law is $\Rightarrow \frac{dQ}{dt}=\sigma A{T}^4$

Stefan's boltzmann's law states that total energy radiated from a surface is proportional to the forth power of its absolute temperature.