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AP EAMCET202120 Aug 2021Evening ShiftChemistryStructure of AtomActual

If the work function for the photoelectron emission of a metal is 3 . 75 eV , then the threshold wave length of the radiation needed for the ejection of the electron is approximately

Options

  1. A315   nm
  2. B280   nm
  3. C330   nm
  4. D290   nm

Correct answer

C. 330   nm

Step-by-step solution

Work function of metal ϕ = 3 . 75   eV = 3 . 75 × 1 . 6 × 10 - 19 V = 6 × 10 - 19 V Planck's constant h = 6 . 63 × 10 - 34 J . s Velocity of light c = 3 × 10 8   m / s Wavelength = hc ϕ = 6 . 63 × 10 - 34 × 3 × 10 8 6 × 10 - 19 = 331 . 5   × 10 - 9 m = 331 . 5   nm Hence, the threshold wave length of the radiation needed for the ejection of the electron is approximately 330   nm .

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