Q 11-14-002NEETNEET 2025Top questionEasy
A pipe open at both ends has a fundamental frequency $f$ in air. The pipe is now dipped vertically in a water drum to half of its length. The fundamental frequency of the air column is now equal to :
Answer: (B) $f$
Open pipe of length $L$: $f = \dfrac{v}{2L}$.
After dipping, the air column has length $\dfrac{L}{2}$ and is closed at the water surface. Closed pipe fundamental:
$$f' = \frac{v}{4(L/2)} = \frac{v}{2L} = f$$
Solution by Sreeraj P, M.Sc Physics