Question

Fundamental frequency of an open pipe is $ {{f}_{0}} $ Fundamental frequency when it is half filled with water is

• A. $ {{f}_{0}} $
• B. $ {{f}_{0}}/2 $
• C. $ 2{{f}_{0}} $
• D. $ 3f $

Answer 1

Answer: (A)

If an open pipe is half submerged in water, it will become a closed organ pipe of length half that of open pipe as shown in figure. So, its Frequency will become,
$ {{f}_{c}}=\frac{v}{4\left( \frac{L}{2} \right)}=\frac{v}{2L}={{f}_{o}} $ i.e., equal to that of open pipe i.e., frequency will remain unchanged.