JEE Mains · Physics · STD 11 - 14. waves and sound
A guitar string of length \(90\,cm\) vibrates with a fundamental frequency of \(120\,Hz.\) The length of the string producing a fundamental frequency of \(180\,Hz\) will be \(...........cm\).
- A \(60\)
- B \(59\)
- C \(58\)
- D \(57\)
Answer & Solution
Correct Answer
(A) \(60\)
Step-by-step Solution
Detailed explanation
\(f =\frac{ nv }{2 \ell}, \text { for fundamental mode } n =1\) \(f =\frac{ v }{2 \ell}\) \(f \propto \frac{1}{\ell}\) \(\frac{ f _1}{ f _2}=\frac{\ell_2}{\ell_1}\) \(\frac{120}{180}=\frac{\ell_2}{90}\) \(\ell_2=60\,cm\)
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