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Q. |
Which of the following Einstein’s coefficient represents spontaneous emission? |
A. | a12 |
B. | a21 |
C. | b12 |
D. | b21 |
Answer» B. a21 | |
Explanation: a21 represents the spontaneous emission of photons. a12 signifies spontaneous absorption.b12 is for stimulated absorption while b21 is for stimulated emission. |
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