How will the fundamental frequency of a closed organ pipe be affected if instead of air, it is filled with a gas heavier than air?

Options

A. there is no change in v
B. v will decrease
C. v will increase
D. v may increase or decrease

Answer

B

Explanation

For a closed pipe, fundamental frequency `v = V/(4L) `
But when it is filled with a heavier gas, the velocity of sound in gas will decrease.
`[ :' V = sqrt((rP)/rho) " or " V propto 1/sqrtrho]`
`:. ` l is constant ` :. ` v will decrease.