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NEET-XII-Physics

11: Dual Nature Of Radiation And Matter

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Qstn# 16-a Prvs-QstnNext-Qstn
  • #16-a
    their momenta,
    (b) the energy of the photon, and
    (c) the kinetic energy of electron.
    Ans : The momentum of an elementary particle is given by de Broglie relation:





    It is clear that momentum depends only on the wavelength of the particle. Since the wavelengths of an electron and a photon are equal, both have an equal momentum.


    (b) The energy of a photon is given by the relation:



    Where,

    Speed of light, c = 3 × 108 m/s



    Therefore, the energy of the photon is 1.243 keV.
    (c) The kinetic energy (K) of an electron having momentum p,is given by the relation:



    Where,

    m = Mass of the electron = 9.1 × 10-31 kg

    p = 6.63 × 10-25 kg m s-1



    Hence, the kinetic energy of the electron is 1.51 eV.
  • #16-b
    the energy of the photon, and
    Ans : The energy of a photon is given by the relation:



    Where,

    Speed of light, c = 3 × 108 m/s



    Therefore, the energy of the photon is 1.243 keV.
  • #16-c
    the kinetic energy of electron.
    Ans : The kinetic energy (K) of an electron having momentum p,is given by the relation:



    Where,

    m = Mass of the electron = 9.1 × 10-31 kg

    p = 6.63 × 10-25 kg m s-1



    Hence, the kinetic energy of the electron is 1.51 eV.