Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
$A$ whistle whose air column is open at both ends has a fundamental frequency of $5100 \mathrm{Hz}$. If the speed of sound in air is $340 \mathrm{ms}^{-1}$, the length of the whistle, in $\mathrm{cm}$, is
PhysicsWaves and SoundWBJEEWBJEE 2014
Options:
  • A $5 / 3$
  • B $10 / 3$
  • C 5
  • D $20 / 3$
Solution:
2889 Upvotes Verified Answer
The correct answer is: $10 / 3$
For an open pipe, the frequency
$$
\begin{array}{l}
f=\frac{v}{2 l} \Rightarrow 5100=\frac{340}{2 \times 1} \\
l=\frac{340}{5100 \times 2} \Rightarrow l=\frac{2}{30 \times 2}=\frac{1}{30} \mathrm{m} \\
l=\frac{100}{30}=\frac{10}{3} \mathrm{cm}
\end{array}
$$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.