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Resonance Tube

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EXPERIMENT NO. 9

Aim : To find the speed of sound in air at room temperature using a resonance tube apparatus
Apparatus : Resonance tube apparatus , tuning forks , rubber pad ,water Theory : If l1 and l2 be the length of the first and second resonance respectively with the tuning fork of frequency ‘(’ , we can write

l1 + e = λ / 4
l2 + e = 3λ / 4 ( where e is the end correction ) Subtracting we get ,
l2 - l1 = λ / 2
λ = 2(l2 - l1)
Speed , V = ( λ
= 2 ( (l2 - l1) Procedure :
1. Set the resonance tube apparatus vertical
2. Fill the tube with water
3. Select a tuning fork and strike it gently on a rubber cork. 4. Hold the vibrating prong horizontally over the mouth of the tube 5. While the tuning fork is vibrating, lower the reservoir. 6. Adjust the reservoir in such a position that a loud sound is heard. 7. This is the first resonance.

8. Note the level reading for the first resonance.
9. Lower the reservoir in the same way to obtain the second resonance. 10. Note the level reading for the second resonance. 11. The difference between the first resonance and the second resonance is λ / 2

12. Calculate the speed of sound using the formula.

Result : Speed of sound at room temperature = ……… m/s

Precautions:
1. The resonance tube should be kept vertical
2. There should be no air bubbles in the tube
3. The tuning fork should be struck gently
4. Keep the stem and the prongs of the tuning fork horizontally Sources of error :
1.The tuning forks may not have the correct...