A pipe open at both ends has a fundamental frequency $f$ 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:

• A

  $2f$
• Correct answer
  B

  $f$
• C

  $\frac{f}{2}$
• D

  $\frac{3f}{4}$

Solution

$f=\frac{v}{2l}$




$f^{\prime }=\frac{v}{4l^{\prime }}=\frac{v}{4\left(\frac{l}{2}\right)}=f$

Hence, the correct answer is option: 'B'.