A) 396 Hz
B) 400 Hz
C) 404 Hz
D) 384 Hz
Correct Answer: A
Solution :
According to law of length of a stretched string \[n\propto \frac{1}{l}\] or, \[{{n}_{1}}{{l}_{1}}={{n}_{2}}{{l}_{2}}\] Given,\[{{n}_{1}}=n-4,{{n}_{2}}=n+4,{{l}_{1}}=50\,cm,\] \[{{l}_{2}}=49\,cm\] Hence, \[(n-4)\times 50=(n+4)\times 49\] or \[50n-200=49n+196\] or \[n=396\,Hz\]You need to login to perform this action.
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