Question

An open tube resonates to a frequency of 156 Hz. When it is dipper so that `(1//4)^(th)` of its length is under water , to what frequency does it resonate ?
A. 150.6Hz
B. 160.6Hz
C. 170.6Hz
D. 180.6Hz

Answer 1

Correct Answer - C
`n_0 = (v)/(2l)`
`n_1=(v)/(4l_1) = (v)/(4(3/4l))`
`n_1=(v)/(3l)`
`n_1/n_0 = (v)/(3l)xx(2l)/(v)=2/3`
`n_1=2/3n_0=2/3xx256`
`n_1=512/3 = 170Hz.`