An electron and proton are separated by a large distance. The electron starts approaching the proton with energy $3\, {eV}$. The proton captures the electrons and forms a hydrogen atom in second excited state. The resulting photon is incident on a photosensitive metal of threshold wavelength $4000\, \mathring {{A}}$. What is the maximum kinetic energy of the emitted photoelectron ? (In ${eV}$)

  • [JEE MAIN 2021]
  • A

    $1.99$

  • B

    $3.3$

  • C

    $1.41$

  • D

    $7.61$

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