JEE Mains · Physics · STD 11 - 14. waves and sound
A string is clamed at both the ends and it is vibrating in its \(4^{th}\) harmonic. The equation of the stationary wave is \(Y =0.3\,sin\,(0.157\,x) \,cos\,(200\pi t)\). The length of the string is ..... \(m\) (all quantities are in \(SI\) units)
- A \(60\)
- B \(80\)
- C \(40\)
- D \(20\)
Answer & Solution
Correct Answer
(B) \(80\)
Step-by-step Solution
Detailed explanation
\(4^{\text {th }}\) harmonic \(4 \frac{\lambda}{2}=\ell \quad ; 2 \lambda=\ell\) From equation \(\frac{2 \pi}{\lambda}=0.157\) \(\lambda=40 ; \quad \ell=2 \lambda=80 \mathrm{m}\)
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