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A pipe open at both ends has a fundamental frequency in air. The pipe 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
2. 3f/4
3. 2f
4. f

Correct answer: f

Solution

When the pipe is half submerged in water, the effective length of the air column is halved, but since the pipe is open at both ends, the fundamental frequency remains the same as it depends on the speed of sound in air and the length of the air column, which is unchanged in terms of its open-end configuration.

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