Question

A glass tube of 1.0 m length is filled with water, the water can be drained out slowly at the bottom of the tube. If a vibrating tuning fork of frequency 500 Hz is brought at the upper and of the tube and the velocity of sound is 330 m/s then the total no. of resonances obtained will be –

• A. 4
• B. 3
• C. 2
• D. 1

Answer 1

Answer: (B)

3

Answer 2

f = 500 Hz

v = 330 m/s

\ l = $\frac { 330 } { 500 }$ = .66 m = 66cm

l₁ = $\frac { \lambda } { 4 }$ = 16.5 cm

l₂ = $\frac { 3 \lambda } { 4 }$ = 49.5 cm

l₃ = $\frac { 5 \lambda } { 4 }$ = 82.5 cm

l₄ = $\frac { 7 \lambda } { 4 }$ = Not possible