Question 422: 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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