Question

A tuning fork is used to produce resonance in glass tube. The length of the air column in the tube can be adjusted by a variable piston, A room temperature of $27^{\circ} C$ two successive resonances are produced at $20\, cm$ and $73\, cm$ column length. If the frequency of the tuning for is $320\, Hz$, the velocity of sound in air at $27^{\circ} C$

• A. 300 m/s
• B. 330 m/s
• C. 350 m/s
• D. 339 m/s

Answer 1

Answer: (D)

339 m/s

Answer 2

$v = 2 (v) [L_2 - L_1]$
$= 2 \times 320 [ 72 - 20] \times 10^{-2}$
$= 339.2 \, ms^{-1}$
$= 339 \, m/s$