Two light sources individually provide intensity I_o at a point. If the sources are operated at the same time and are coherent but out of phase 30°, what is the intensity at that point? A)3.7 I_o B)2.0 I_o C)3.0 I_o D)2.8 I_o E)1.0 I_o

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Quizplus · Accepted Answer

The intensity at that point is given by I = 4I_ocos²(φ/2), where φ is the phase difference between the two sources. In this case, φ = 30°, so I = 4I_ocos²(15°) = 3.7I_o.

Two Light Sources Individually Provide Intensity Io at a Point

Two Light Sources Individually Provide Intensity I_o at a Point