A cylinderical tube open at both ends, has a fundamental frequency f in air. The tube is dipped vertically in water so that half of it is in water. The fundamental frequency of air column is now

Options

A. `f//2`
B. `3f//4`
C. f
D. `2f`

Answer

c

Explanation

For open organ pipe fundamental frequency `fv/(2l)`.
When tube is half immersed in water, the organ pipe
become closed and length of vibrating air column
becomes half (i.e. 1/2).
`therefore` New fundamental frequency,`f'= v/(4(l/2))=v/(2l)=f`