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In photoelectric effect an em-wave is incident on a metal surface and electrons are ejected from the surface. If the work function of the metal is 2.14 eV and stopping potential is 2 V , what is the wavelength of the em-wave ? (Given hc =1242 eVnm where h is the Planck's constant and c is the speed of light in vaccum.)

Options

  1. A300 nm
  2. B400 nm
  3. C600 nm
  4. D200 nm

Correct answer

A. 300 nm

Step-by-step solution

aligned & =2.14 & V_S=2 ~V aligned Using photoelectric equation. aligned & h c =2.14+2=4.14 eV & = 1242 4.14 =300 ~nm aligned

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