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In laser production the state in which more atoms are in the upper state than in the lower one is called_____________?

Correct answer: C. Inverted population

  • A. Metal stable state
  • B. Normal state
  • C. Inverted population
  • D. All the above

Explanation

When more atoms occupy the upper energy level than the lower level, the condition is called population inversion, which is necessary for laser action. The likely mistake is choosing normal state, where the lower energy level normally contains more atoms.

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Quantum theory treats electromagnetic radiation as packets of energy called photons, with energy proportional to frequency through E equals hf. The topic covers Planck's hypothesis, photon momentum, the photoelectric effect, threshold frequency, work function and wave particle duality, distinguishing quantised energy exchange from classical continuous radiation.

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