ExamBro
ExamBro
MHT CET · Physics · Waves and Sound

A sonometer wire of length \(25 \mathrm{~cm}\) vibrates in unison with a tuning fork. When its length in decreased by \(1 \mathrm{~cm}, 6\) beats are heard per second. What is the frequency of the tuning fork?

  1. A \(200 \mathrm{~Hz}\)
  2. B \(72 \mathrm{~Hz}\)
  3. C \(100 \mathrm{~Hz}\)
  4. D \(144 \mathrm{~Hz}\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(144 \mathrm{~Hz}\)

Step-by-step Solution

Detailed explanation

When length decrease, the frequency of wire will increase. If \(n\) is the frequency of the tuning fork, then we have
\(
\begin{aligned}
& \mathrm{n} \times 25=(\mathrm{n}+6) \times 24 \\
& \therefore \mathrm{n}=144 \mathrm{~Hz}
\end{aligned}
\)