# Figure shows a tube having sound source at one end and observe at other end. Source produces frequencies upto 10000 Hz. Speed of sound is 400 m//s

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Figure shows a tube having sound source at one end and observe at other end. Source produces frequencies upto 10000 Hz. Speed of sound is 400 m//s. Find the frequencies at which person hears maximum intensity. by (85.2k points)
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The sound wave bifurcates at the juction of the straight and the rectangular parts. The wave through the straight part travels a distance p_(1) = 10 cm  and the wave through the rectangular part travels a distance p_(2) = 3 xx 10 xm = 30 before they mwwt agian and travel to the receiver. The path difference between the two wave received, therefore.
Deltap = p_(2) - p_(1) = 30 cm - 10 cm = 20 cm
The wavelength of either wave is (v)/(upsilon) rArr (400 m//s)/(upsilon). For constructive interference, Deltap = nlambda, where n is an integer.
or, Deltap = n.(v)/(v) rArr v = (n.v)/(Deltap)
rArr v = (400)/(0.1) = 4000 n
Thus, the frequencies within the specified range which cause maximum of intensity are
4000 xx 1 Hz, 4000 xx 2 Hz