Get Answers to all your Questions

header-bg qa

Two identical string instruments have frequency of 100 \mathrm{~Hz}. If tension in one of them increases by 4 \% and they are sounded together, then the number of beats - in 1\: \mathrm{sec} are -
 

Option: 1

1


Option: 2

8


Option: 3

4


Option: 4

2


Answers (1)

best_answer

Use, \mathrm{f \propto \sqrt{\bar{T}}\: or \: f \alpha T^{1 / 2}}
\% increase in f=\frac{1}{2}(% increases in \mathrm{T})

\mathrm{ f=\frac{1}{2} \times 4=2 \% }

\mathrm{ f_1=100 \mathrm{~Hz}}

and \mathrm{f_2=100+2 \% \: of \: 100=102 \mathrm{~Hz}}

Beat frequency, \mathrm{f=f_2-f_1}

                        \mathrm{f=2 \mathrm{Hz}.}

Hence option 4 is correct.

Posted by

Deependra Verma

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE