A closed organ pipe has length `L`. The air in it is vibrating in third overtone with maximum amplitude a . The amplitude at distance`(L)/(7)` from closed of the pipe is a) 0 b) a c) a/2 d) data insufficient

Options

A. ` a `
B. ` ( a ) /( 2 ) `
C. ` (sqrt3 a ) / ( 2 ) `
D. ` ( 1 ) /( sqrt2 ) a `

Answer

A

Explanation

For ` 3^(rd) ` overtone

` l = ( 7lamda ) /( 4) , ( lamda ) / ( 4) = ( l ) /( 7) `
Hence the amplitude at P at a distance ` ( l) /( 7) ` from closed end is 'a' because there is an antinode at that point.