Question

A whistle whose air column is open at both ends has a fundamental frequency of 5100 Hz. If the speed of sound in airis $340m{s}^{-1}$, the wavelength of the whistle, in cm is:

• A. $5/3$
• B. $10/3$
• C. $5$
• D. $20/3$

Answer 1

The correct option is B $10/3$

The fundamental frequency of air column open at both ends is given by

$f_0=\frac{c}{2l}$

$⟹l=\frac{c}{2f_0}$

$⟹l=\frac{340m/s}{2\times 5100Hz}$

$=\frac{340}{2\times 5100}\times 100cm$

$=\frac{10}{3}cm$