A glass tube 1.5m long and open at both ends is immered vertically in a water tank completely. A tuning fork of 600 Hz is vibrated and kept at the upper end of tube is gradually raised out of water. The total number of resonances heard before when the tube comes out of water, taking `vv=330ms^-1`.

Options

A. 12
B. 6
C. 8
D. 4

Answer

B

Explanation

Frequency of tube =`v/(4l)`
At resonance `v/(4l)`=600
Let the tube is xm above the water, `implies330/(4xxx)=600`
`x=330/(4xx600)`
=0.1375m
Other resonace will occur at 3x,5x,7x……..
i.e.,
At 0.4125m,0.6875m,0.9625m,1.2375m,1.5125m
Therfore, total 6 resonance will be obtained