Question 356: Waves

Question

A sonometer wire $$49 \mathrm{~cm}$$ long is in unison with a tuning fork of frequency '$$n$$'. If the length of the wire is decreased by $$1 \mathrm{~cm}$$ and it is vibrated with the same tuning fork, 6 beats are heard per second. The value of '$$n$$' is

Accepted Answer

$$\begin{array}{ll} 
& \mathrm{n}_1 \mathrm{~L}_1=\mathrm{n}_2 \mathrm{~L}_2 \
	herefore \quad & \mathrm{n}_1 	imes 49=\mathrm{n}_2 	imes 48 \
	herefore \quad & \mathrm{n}_2=\frac{49}{48} \mathrm{n}_1
\end{array}$$
Given that, beat frequency, $$\left|\mathrm{n}_1-\mathrm{n}_2ight|=6$$
$$\begin{aligned}
& 	herefore \quad\left|\mathrm{n}_1-\frac{49}{48} \mathrm{n}_1ight|=6 \
& 	herefore \quad \frac{\mathrm{n}_1}{48}=6 \
& 	herefore \quad \mathrm{n}_1=288 \mathrm{~Hz}
\end{aligned}$$

Answer

256 Hz

Answer

288 Hz

Answer

320 Hz

Answer

384 Hz

Waves

A sonometer wire $49 \mathrm{~cm} long is in unison with a tuning fork of frequency 'n'. If the length of the wire is decreased by 1 \mathrm{~cm} and it is vibrated with the same tuning fork, 6 beats are heard per second. The value of 'n$' is

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