MCQ
If the velocity of sound in air is $336 m/s$. The maximum length of a closed pipe that would produce a just audible sound will be
- A$3.2 cm$
- ✓$4.2 m$
- C$4.2 cm$
- D$3.2 m$
✓
Answer
Correct option: B.
$4.2 m$
b
(b) Minimum audible frequency $= 20 Hz$.
$ \Rightarrow $ $\frac{v}{{4l}} = 20 \Rightarrow l = \frac{{336}}{{4 \times 20}} = 4.2$$m$
(b) Minimum audible frequency $= 20 Hz$.
$ \Rightarrow $ $\frac{v}{{4l}} = 20 \Rightarrow l = \frac{{336}}{{4 \times 20}} = 4.2$$m$
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