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A closed and an open organ pipe have same lengths. If the ratio of frequencies of their seventh overtones is ( a - 1a ) then the value of a is .
16
Closed pipe (odd harmonics only): 7th overtone = 15th harmonic
fc = 15v4L
Open pipe (all harmonics): 7th overtone = 8th harmonic
fo = 8v2L = 16v4L
fcfo = 1516 = a - 1a a = 16
Answer: 16
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