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Consider figure for photoemission. How w...

Consider figure for photoemission. How would you reconcile with momentum-conservatin? Note light (photons) have momentum in a different direction than the emitted electrons.

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When a photon interacts with an atom, then its momentum is transferred to the electrons as well as to the nucleus . If we consider the momentum imparted to the nucleus also then, momentum conservation be side to be applicable here also.
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Consider fig. for photoemission. How would you recocile with momentum-conservation? Note light (photons) have momentum in a different direction than the emitted electrons.

A parallel beam of electrons , travelling in x - direction , falls on a slit of width d (see the figure) . If after passing the slit, an electron acquires momentum P_y in the y direction, then for a majority of electrons passing through the slit , (h is Planck's constant)

Knowledge Check

  • A parallel beam of electrons travelling in X-direction falls on a slit of width d (see figure). If after passing the slit, an electron acquires momentum p_y in the Y-direction, then for a majority of electrons passing through the slit (h is Planck's constant):

    A
    `|p_y|d = h`
    B
    `|p_y|d gt h`
    C
    `|p_y|d lt h`
    D
    `|p_y|d gt gt h`

  • A parallel beam of electrons travelling in x-direction falls on a slit of width d (see figure). If after passing the slit, an electron acquires momentum p_y in the y-direction then for a majority of electrons passing through the slit (h is Planck's constant):

    A
    `|P_y|d gt h`
    B
    `|P_y| d lt h`
    C
    `|P_y|d = h`
    D
    `|P_y| d gt gt h`

  • The momentum of a photon having energy equal to the rest energy of an electron is

    A
    zero
    B
    `2.73 xx 10^(-22)kg ms^(-1)`
    C
    `1.99 xx 10^(-24)kg ms^(-1)`
    D
    infinite

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