Question

In a resonance tube, using a tuning fork of frequency $325 \, Hz$ , two successive resonance length are observed as $25.4 \, cm$ and $77.4 \, cm$ respectively. The velocity of sound in air is

• A. $338 \, m \, s^{- 1}$
• B. $328 \, m \, s^{- 1}$
• C. $330 \, m \, s^{- 1}$
• D. $320 \, m \, s^{- 1}$

Answer 1

Answer: (A)

$v=2n\left(l_{2} - l_{1}\right)=2\times 325\left(77.4 - 25.4 \, \right)cm \, s^{- 1}$

$=\frac{650 \times 52}{100} \, m \, s^{- 1}=338 \, m \, s^{- 1}$