A) \[300\,\,Hz\]
B) \[500\,\,Hz\]
C) \[1000\,\,Hz\]
D) \[400\,\,Hz\]
Correct Answer: A
Solution :
Key Idea: Beats = Difference in frequencies. The frequency of vibration \[n=\frac{1}{2l}\sqrt{\frac{T}{m}}\] ? (i) Given, \[n'=n+\frac{3}{2},\,\,T'=T'+\frac{T}{100}=\frac{101T}{100}\] \[\therefore \] \[n+\frac{3}{2}=\frac{1}{2l}\sqrt{\frac{101T}{100m}}\] \[\Rightarrow \] \[n+\frac{3}{2}=1.005\times \frac{1}{2l}\sqrt{\frac{T}{m}}\] ? (ii) From Eqs. (i) and (ii), we get \[n+\frac{3}{2}=1.005\times n\] \[\Rightarrow \] \[n=300\,\,Hz\]You need to login to perform this action.
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