A two level system in a thermal (black body) environment can decay from the excited state by both spontaneous and thermally stimulated emission. at room tempera

A two level system in a thermal (black body) environment can decay from the excited state by both spontaneous and thermally stimulated emission. At room temperature Q36. (300 K the frequency below which thermal emission dominates over spontaneous emission is nearest to (a) 103 HeE (b) 10° Hz (c) 10 Hz (d) 10 H