MCQ
Consider a spherical shell of radius $R$ at temperature $T$. The black body radiation inside it can be considered as an ideal gas of photons with internal energy per unit volume$E=$ $\frac{U}{V} \propto {T^4}$ and pressure $P = \frac{1}{3}\left( {\frac{U}{V}} \right)$ If the shell now undergoes an adiabatic expansion the relation between $T$ and $R$ is
- A$T \propto {e^{ - 3R}}\;\;\;\;\;\;\;\;\;\;\;\;$
- ✓$\;T \propto \frac{1}{R}$
- C$\;T \propto \frac{1}{{{R^3}}}$
- D$\;T \propto {e^{ - R}}$
