Question

An air column in a pipe, which is closed at one end, will be in resonance with a vibrating tuning fork of frequency $264Hz$ if the length of the column in cm is (velocity of sound = $330m/s$)

• A. 125.00
• B. 93.75
• C. 62.50
• D. 187.50

Answer 1

Answer: (B)

Given : Frequency of tuning fork, n = 264 Hz
Length of column L = ?
For closed organ pipe
$n=\frac{v}{4l}$
$\Rightarrow l=\frac{v}{4n}=\frac{330}{4\times 264}=0.3125$
or, $l=0.3125\times 100=31.25cm$
In case of closed organ pipe only odd harmonics are possible.
Therefore value of $I$ will be $\left(2n-1\right)l$ Hence option $\left(b\right)i.e.3\times 31.25=93.75cm$ is correct.