Q. Two open organ pipes of length $25\ cm$ and $25.5\ cm$ produce $10\ beat/sec.$ The velocity of sound will be
A) $255\ m/s$
B) $250\ m/s$
C) $350\ m/s$
D) None of these
Explanation
(a) $\mathrm{\Delta}n = n_{1} - n_{2} \Rightarrow 10 = \frac{v}{2l_{1}} - \frac{v}{2l_{2}} = \frac{v}{2}\left\lbrack \frac{1}{l_{1}} - \frac{1}{l_{2}} \right\rbrack$
$\Rightarrow 10 = \frac{v}{2}\left\lbrack \frac{1}{0.25} - \frac{1}{0.255} \right\rbrack \Rightarrow v = 255m/s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.