Question 384: Waves

Question

A tuning fork of frequency '$n$' is held near the open end of tube which is closed at the other end and the lengths are adjusted until resonance occurs. The first resonance occurs at length $L_1$ and immediate next resonance occurs at length $L_2$. The speed of sound in air is

Accepted Answer

For first resonance $L_1=\frac{\lambda}{4}$
For second resonance $\mathrm{L}_2=\frac{3 \lambda}{4}$
$\begin{aligned}
	herefore \quad & \mathrm{L}_2-\mathrm{L}_1=\frac{\lambda}{2} 	ext { or } \lambda=2\left(\mathrm{~L}_2-\mathrm{L}_1ight) \
& \mathrm{V}=\mathrm{n} \lambda=2 \mathrm{n}\left(\mathrm{L}_2-\mathrm{L}_1ight)
\end{aligned}
$

Answer

$n\left(L_2-L_1\right)$

Answer

$\frac{\mathrm{n}\left(\mathrm{L}_2-\mathrm{L}_1\right)}{2}$

Answer

$2 n\left(L_2-L_1\right)$

Answer

$\frac{\mathrm{n}\left(\mathrm{L}_2+\mathrm{L}_1\right)}{2}$

Waves

A tuning fork of frequency 'n' is held near the open end of tube which is closed at the other end and the lengths are adjusted until resonance occurs. The first resonance occurs at length L_1 and immediate next resonance occurs at length L_2. The speed of sound in air is

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