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Quantum theory practice

QCE Physics · Original practice questions with worked solutions

All quantum theory practice questions

56 original questions · Page 3 of 3

  1. Q272 · Original practice · 4 marks
    Metals A and B have work functions WA=3.00×10−19 JW_A=3.00\times10^{-19}\,\mathrm J and WB=4.00×10−19 JW_B=4.00\times10^{-19}\,\mathrm J. Use h=6.626×10−34 J sh=6.626\times10^{-34}\,\mathrm{J\,s}.
    Quantum theory
  2. Q273 · Original practice · 1 mark
    An atom has three bound energies −9.00-9.00, −5.00-5.00 and −2.00 eV-2.00\,\mathrm{eV}. An electron starts in the middle level. Ignore recoil, line broadening and multiphoton processes. Which photon can cause a transition to another bound level?
    Quantum theory
  3. Q274 · Original practice · 5 marks
    In a photoelectric experiment the collector potential relative to the emitter at zero photocurrent is Vc=−VsV_c=-V_s, where VsV_s is the positive stopping-potential magnitude. A fitted graph of VsV_s against frequency passes through (6.00×1014 Hz,0.500 V)(6.00\times10^{14}\,\mathrm{Hz},0.500\,\mathrm V) and (9.00×1014 Hz,1.74 V)(9.00\times10^{14}\,\mathrm{Hz},1.74\,\mathrm V). Use…
    Quantum theory
  4. Q275 · Original practice · 3 marks
    A gas initially has its electrons in the ground state. Its absorption spectrum has narrow lines at 310 nm310\,\mathrm{nm} and 620 nm620\,\mathrm{nm}. Candidate model X has levels 00, 2.002.00 and 4.00 eV4.00\,\mathrm{eV}; model Y has levels 00, 3.003.00 and 4.00 eV4.00\,\mathrm{eV}. Assume only these levels and neglect recoil. Use hc=1240 eV nmhc=1240\,\mathrm{eV\,nm}.
    Quantum theory
  5. Q276 · Original practice · 3 marks
    Hydrogen emits photons when electrons end at nf=2n_f=2. Use R=1.097×107 m−1R=1.097\times10^7\,\mathrm{m^{-1}}.
    Quantum theory
  6. Q277 · Original practice · 4 marks
    The diagram shows an idealised atom with three bound levels −8.00-8.00, −5.00-5.00 and −1.00 eV-1.00\,\mathrm{eV}. An electron absorbs a photon from the ground state to the top level, then returns through the middle level in two emission steps. Use hc=1240 eV nmhc=1240\,\mathrm{eV\,nm}.
    Quantum theory
  7. Q278 · Original practice · 3 marks
    An electron in an allowed Bohr orbit satisfies nλ=2πrn\lambda=2\pi r and p=h/λp=h/\lambda. Treat its momentum as nonrelativistic.
    Quantum theory
  8. Q284 · Original practice · 7 marks
    Light illuminates a metal of work function W=2.00×10−19 JW=2.00\times10^{-19}\,\mathrm J. The most energetic emitted electrons enter a uniform 1.00×10−3 T1.00\times10^{-3}\,\mathrm T magnetic field perpendicular to their velocity and follow circular paths of radius 2.00×10−3 m2.00\times10^{-3}\,\mathrm m. Assume single-photon emission and nonrelativistic electrons. Use…
    Quantum theory