Q. If $L_{1}$ and $L_{2}$ are the lengths of the first and second resonating air columns in a resonance tube, then the wavelength of the note produced is
A) $2(L_{2} + L_{1})$
B) $2(L_{2} - L_{1})$
C) $2\left( L_{2} - \frac{L_{1}}{2} \right)$
D) $2\left( L_{2} + \frac{L_{1}}{2} \right)$
Explanation
(b) $if\ L_{1}and\ L_{2}$ are the first and second resonances, then we have
$L_{1} + e = \frac{\lambda}{4}and\ L_{2} + e = \frac{3\lambda}{4}$
$\therefore\ \ \ L - 2 - L_{1} = \frac{\lambda}{2}$
$\Longrightarrow \lambda = 2\left( L_{2} - L_{1} \right)$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.