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A cylindrical tube, open at both ends, has a fundamental frequency f in air. The tube is dipped vertically in water so that half of it is in water. The fundamental frequency of the air-column is now:

1. f
2. f/2
3. 3f/4
4. 2f

Correct answer: f

Solution

The fundamental frequency of a tube open at both ends is determined by the length of the air column. When half of the tube is submerged in water, the length of the air column remains unchanged, thus the fundamental frequency remains the same.

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