Question

A glass tube of length 1.0 m is completely filled with water. A vibrating tuning fork of frequency 500 Hz is kept over the mouth of the tube and the water is drained out slowly at the bottom of the tube. If velocity of sound in air is 330 m/sec then total number of resonance that occure will be :

• A. 1
• B. 3
• C. 2
• D. 5

Answer 1

The correct option is B 3

$\frac{\lambda }{4}=\frac{V}{4f}$ = 0.165m

$\frac{\lambda }{4},\frac{3\lambda }{4},\frac{5\lambda }{4}$

are possible with in 1 m length

suggestions of resonances respective at λ/4, 3λ/4, 5λ/4

​so total number of resonances​ obtained​will be 3

so B option is the correct answer