Help with a MCQ (1 Viewer)
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wizzkids
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This looks like a mistake (that's a very suspicious looking 45 degrees). Recall that the expression for the positions of intensity maxima says:
)
. Look closely at the diagram and you will notice that the paths converge, not at a maximum, but at a minimum. Therefore n = 1.5 (approximately) in this question, and theta = 45 degrees, hence 
(approximately). On the other hand, if the angle was 30 degrees, then the answer would come out as exactly 
. Dodgy question, imho.
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