Question

When an air column of length $l$ open at both ends produces its fundamental note, the wavelength is given by :

• A. $\lambda =l$
• B. $\lambda =2l$
• C. $\lambda =4$
• D. $\lambda =3l$

Answer 1

Answer: (B)

$\lambda =2l$

At both the open ends antinodes are formed. Distance between two antinode is $\frac{\lambda }{2}$.

$\frac{\lambda }{2}=l\Rightarrow \lambda =2l$