Question

A tube of length 1.05 m is closed at one end. If the velocity of sound in air is 336m/s, then the fundamental and the next higher overtone frequencies are (in Hz)

• A. 80, 160
• B. 80, 240
• C. 160, 320
• D. 160, 480

Answer 1

Answer: (B)

80, 240

Fundamental frequency, $f=\frac{v}{4l}=\frac{336}{4\times 1.05}$ $=\frac{336}{4.2}=80Hz$

First overtone $=\frac{3v}{4\lambda }=3\left(80\right)=240Hz$