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Q.
A tube with both ends closed has same set of natural frequency as
Oscillations
Solution:
A tube with both ends closed has same set of natural frequency as both end open organ pipe as in both the cases max wavelength will be $L =\lambda / 2$.
In case of both end closed, at the ends nodes will be formed, in the case of both end open, at the ends antinodes will be formed.
And frequency $=$ velocity / wavelength or $\lambda$.