A resonance jar of length 1m and small diameter is completely filled with water. The water can be slowly removed through a tube fixed near the bottom of the jar.
A tuning fork of frequency 550 Hz is kept vibrating near the upper end of the jar. If the velocity of sound is 330 m/s, then the maximum number of resonances that can be heard will be

Options

A. 4
B. 1
C. 2
D. 3

Answer

D

Explanation

`lambda = (33000)/550 = 60 cm :. lambda/4 = 15 cm `
Resonance occurs when `l = lambda/4, (3 lambda)/4, (5 lambda)/4, (7 lambda)/4`
i.e., when ` l = 15, 45 , 75 , 105 ` cm etc. As it is not possible to get 105 cm ` :. ` No. of resonances = 3