Question

What is the frequency of the sound produced in Hertz if an open pipe produces a standing wave as shown? (Velocity of sound $=360m/s)$

• A. $900Hz$
• B. $1800Hz$
• C. $720Hz$
• D. $1440Hz$
• E. $2700Hz$

Answer 1

The correct option is B $1800Hz$

Given : $L=40$ cm $=0.4$ m $v=360m/s$

$\therefore$ $L=2\lambda$

OR $0.4=2\lambda$ $⟹\lambda =0.2$ m

Now frequency of the wave $\nu =\frac{v}{\lambda }=\frac{360}{0.2}=1800$ $Hz$