Asked in NUMS 2019 (cancelled sitting) 2019Moderate

If the wavelength of K X-ray from Cu is 1.337 x 10^-10m, then the energy difference between two levels from which transition results will be:

Correct answer: E. 9.31 keV

  • A. 9.03 KeV
  • B. 9.90 KeV
  • C. 90.3 KeV
  • D. 8.03 KeV
  • E. 9.31 keV

Explanation

he energy difference between two levels can be calculated using the formula:ΔE = hc/λwhere h is Planck's constant, c is the speed of light, and λ is the wavelength.Substituting the given values:ΔE = (6.626 x 10-34 J s) x (3.0 x 108 m/s) / (1.337 x 10-10 m)ΔE = 1.49 x 10-15 JConverting the energy to keV:ΔE = (1.49 x 10-15 J) / (1.602 x 10-16 J/keV) = 9.31 keVTherefore, the correct answer is E) 9.31 KeV.

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