For two equal coherent beams each of intensity \(I_0\), write the intensity as a function of phase difference \(\delta\).
Question 2
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For two equal coherent beams each of intensity \(I_0\), find \(I\) at \(\delta=0\) and \(\delta=\pi\).
Question 3
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Write the general two-beam interference intensity formula for intensities \(I_1\) and \(I_2\).
Question 4
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Two equal beams each have \(I_0=5.0\,\mathrm{W\,m^{-2}}\). Find the maximum and minimum intensities.
Question 5
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Two coherent beams have intensities \(16\) and \(9\,\mathrm{W\,m^{-2}}\). Find \(I_{\max}\) and \(I_{\min}\).
Question 6
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For \(I_1=16\), \(I_2=9\,\mathrm{W\,m^{-2}}\), find the intensity when \(\delta=\pi/2\).
Question 7
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A pattern has \(I_{\max}=49\) and \(I_{\min}=1\,\mathrm{W\,m^{-2}}\). Find the visibility.
Question 8
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A double-slit point has path difference \(\lambda/3\). For equal beams each of intensity \(I_0\), find the resultant intensity.
Question 9
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Derive \(I=4I_0\cos^2(\delta/2)\) for two equal coherent beams.
Question 10
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Derive the unequal-beam maximum and minimum intensities from the general formula.
Question 11
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A measured interference pattern has visibility \(V=0.80\). If \(I_{\max}=90\,\mathrm{W\,m^{-2}}\), find \(I_{\min}\).
Question 12
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Two beams have intensity ratio \(9:1\). Find the visibility of their interference fringes.
Question 13
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A phase difference fluctuates uniformly over \(0\) to \(2\pi\) during exposure. Use the intensity formula to find the observed average.
Question 14
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A pattern has nonzero minimum intensity. Give two distinct physical reasons and connect each to a model parameter.
Question 15
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A two-beam pattern has \(I_{\max}=36\) and \(I_{\min}=4\,\mathrm{W\,m^{-2}}\). Recover the individual beam intensities assuming perfect coherence.
Question 16
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For equal beams, find the phase width around a maximum for which intensity is at least half the maximum.
Question 17
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A detector saturates at \(30\,\mathrm{W\,m^{-2}}\). Two equal coherent beams each have \(I_0=10\,\mathrm{W\,m^{-2}}\). Which phase range causes saturation?
Question 18
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Show that two coherent beams can produce local intensity greater than the sum of their separate intensities without violating energy conservation.
Question 19
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For unequal beams, derive visibility directly in terms of \(I_1\) and \(I_2\).
Question 20
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Prove that maximum fringe visibility requires equal beam intensities.