Question

A pipe closed at one end has length $83$ cm. The number of possible natural oscillations of air column whose frequencies lie below $100$Hz are (velocity of sound in air = $332$ m/s)

• A. $0$
• B. $4$
• C. $5$
• D. $6$

Answer 1

The correct option is A $0$

We know that for a pipe closed at one end, a frequency is given by:-

$f=\frac{n\times v}{4L}$

$v=$ speed of sound=$332m/s$

$L=$length of pipe=$83cm=0.83m$

$n=0,1,\mathrm{2...}$

$f=\frac{1\times 332}{4\times 0.83}$

$⟹f=100Hz$

Hence, no natural oscillation of frequency less than $100Hz$.