The work function of a photosensitive metal is . What is the threshold wavelength above which photoelectric emission CANNOT occur? ()

Answer and explanation

Correct answer: D.

  1. Step 1: The threshold wavelength is related to the work function by .
  2. Step 2: Solve for threshold wavelength: .
  3. Step 3: Substitute values: . Photons with carry energy less than and cannot eject photoelectrons.
Answer
.
Why not the others: corresponds to a work function of ; corresponds to ; is the edge of the visible spectrum.

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