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Two plane harmonic sound waves are expressed by the equations: y1 (x,t)=Acos(0.5πx-100πt) y2 (x,t)=Acos(0.46πx-92πt) All the parameters are in mks system. How many times does an observer hear maximum intensity in one second?

Two plane harmonic sound waves are expressed by the equations: y1 (x,t)=Acos(0.5πx-100πt) y2 (x,t)=Acos(0.46πx-92πt) All the parameters are in mks system. How many times does an observer hear maximum intensity in one second? Correct Answer 4

For first wave, ω1=2πv1=100π v1=50Hz Beat frequency=v1-v2=4Hz Hence the intensity of sound becomes maximum 4 times in one second.

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