Teaching MPPSC Assistant Professor Mock Test Series 2025 Physical Sciences Atomic & Molecular Physics
Consider a system of identical atoms in equilibrium with blackbody radiation in a cavity at temperature T. The equilibrium probabilities for each atom being in the ground state |0〉 and an excited state |1〉 are P0 and P1 respectively. Let n be the average number of photons in a mode in the cavity that causes transition between the two states. Let W0→1 and W1→0 denote, respectively, the squares of the matrix elements corresponding to the atomic transitions \(|0\rangle \rightarrow|1\rangle \text { and }|1\rangle \rightarrow|0\rangle\) Which of the following equations hold in equilibrium?
1
\(P_0 n W_{0 \rightarrow 1}=P_1 W_{1 \rightarrow 0}\)
2
\(P_0 n W_{0 \rightarrow 1}=P_1 n W_{1 \rightarrow 0}\)
3
\(P_0 n W_{0 \rightarrow 1}=P_1 W_{1 \rightarrow 0}-P_1 n W_{1 \rightarrow 0}\)
4
\(P_0 n W_{0 \rightarrow 1}=P_1 W_{1 \rightarrow 0}+P_1 n W_{1 \rightarrow 0}\)