Search any question & find its solution
 Question:  
Answered & Verified by Expert
 
 5 beats/ second are heard when a turning fork is sounded with a sonometer wire under tension, when the length of the sonometer wire is either $0.95 \mathrm{~m}$ or $1 \mathrm{~m}$. The frequency of the fork will be:
  Options:
            Solution: 
    2363 Upvotes
  
Verified Answer
 
 
The correct answer is:
$195 \mathrm{~Hz}$
 
 $195 \mathrm{~Hz}$
Probable frequencies of tuning fork be $n \pm$ 5
Frequency of sonometer wire, $n \propto \frac{1}{l}$
$$
\begin{aligned}
&\therefore \frac{n+5}{n-5}=\frac{100}{95} \Rightarrow 95(n+5)=100(n-5) \\
&\text { or, } 95 n+475=100 n-500 \\
&\text { or, } 5 n=975 \\
&\text { or, } n=\frac{975}{5}=195 \mathrm{~Hz}
\end{aligned}
$$
 Frequency of sonometer wire, $n \propto \frac{1}{l}$
$$
\begin{aligned}
&\therefore \frac{n+5}{n-5}=\frac{100}{95} \Rightarrow 95(n+5)=100(n-5) \\
&\text { or, } 95 n+475=100 n-500 \\
&\text { or, } 5 n=975 \\
&\text { or, } n=\frac{975}{5}=195 \mathrm{~Hz}
\end{aligned}
$$
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.