Questions
Question 1
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State the position-momentum uncertainty principle.
Question 2
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What is \(\hbar\) in terms of \(h\)?
Question 3
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Is the uncertainty principle mainly a statement about poor instruments?
Question 4
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An electron is localized to \(0.100\,\mathrm{nm}\). Estimate the minimum momentum uncertainty using \(\hbar=1.05\times10^{-34}\,\mathrm{J\,s}\).
Question 5
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A particle has \(\Delta x=1.0\times10^{-12}\,\mathrm{m}\). Estimate the minimum \(\Delta p\).
Question 6
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If \(\Delta x\) is made ten times smaller, what happens to the minimum possible \(\Delta p\)?
Question 7
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A particle has \(\Delta p=2.0\times10^{-24}\,\mathrm{kg\,m\,s^{-1}}\). Find the minimum \(\Delta x\).
Question 8
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State the energy-time uncertainty estimate.
Question 9
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A state lasts \(1.0\times10^{-9}\,\mathrm{s}\). Estimate the minimum energy uncertainty.
Question 10
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Convert \(5.25\times10^{-26}\,\mathrm{J}\) to eV using \(1\,\mathrm{eV}=1.60\times10^{-19}\,\mathrm{J}\).
Question 11
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Why does a narrow slit imply a spread in transverse momentum?
Question 12
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A beam is localized to a slit of width \(a\). What rough momentum spread scale follows from de Broglie reasoning?
Question 13
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Can \(\Delta x\) and \(\Delta p\) both be zero for the same particle state?
Question 14
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If \(\Delta x\) is very large, does the uncertainty principle force \(\Delta p\) to be large?
Question 15
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A particle is localized to nuclear scale, \(\Delta x=1.0\times10^{-15}\,\mathrm{m}\). Estimate \(\Delta p_{\min}\).
Question 16
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Why is confinement energy important for light particles such as electrons?
Question 17
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A short-lived excited state has lifetime \(2.0\times10^{-15}\,\mathrm{s}\). Estimate its minimum energy width in joules.
Question 18
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Convert the energy width in question 17 to eV.
Question 19
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Explain why the uncertainty principle is consistent with diffraction.
Question 20
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Derive the minimum momentum uncertainty for a given position uncertainty.