Question

A cylindrical tube (L = 125 cm) is resonant with a tuning fork of frequency 330 Hz. If it is filling by water then to get resonance again, minimum length of water column is (`V_air` = 330 m/s) -
A. 50 cm
B. 60 cm
C. 25 cm
D. 20 cm

Answer 1

Correct Answer - A
`f=((2n-1)v)/(4l)`
`l=((2n-1)v)/(4f)=((2n-1)xx330)/(4xx330)=((2n-1))/(4)`
`l=1/4m, 3/4m = 25cm, 75cm.`
`therefore` Minimum height of water column
=125-75=50cm