Question:

In an experiment with a closed organ pipe, it is filled with water by \(\left(\frac{1}{5}\right)^{th}\) of its volume. The frequency of the fundamental note will change by

Show Hint

Filling one fifth of the length with water shortens the air column to four fifths, and frequency is inversely proportional to length.
Updated On: Nov 12, 2026
  • \(25\%\)
  • \(20\%\)
  • \(-20\%\)
  • \(-25\%\)
Show Solution
collegedunia
Verified By Collegedunia

The Correct Option is A

Solution and Explanation

Step 1: Understanding the Concept
For a closed pipe the fundamental frequency is \(f=\dfrac{v}{4L}\), so \(f\propto\dfrac{1}{L}\).

Step 2: New length
Water fills \(\dfrac{1}{5}\) of the pipe, so the air column is \(L'=\dfrac{4L}{5}\).

Step 3: New frequency
\(f'=\dfrac{v}{4L'}=\dfrac{5}{4}f\).

Step 4: Percentage change
\(\dfrac{f'-f}{f}\times100=25\%\), option (A).

Final Answer:
The frequency increases by 25 percent. \[ \boxed{\text{(A) }25\%} \]
Was this answer helpful?
0
0