Question

A pipe closed at one end has length 83 cm. The number of possible natural oscillations of air column whose frequencies lie below 1000 Hz are ______. (velocity of sound in air = 332 m/s)

Options

• 3

• 4

• 5

• 6

Answer 1

A pipe closed at one end has length 83 cm. The number of possible natural oscillations of air column whose frequencies lie below 1000 Hz are 5. (velocity of sound in air = 332 m/s)

Explanation:

In case of closed organ pipe, fundamental frequency

n `"V"/(4"L")= 332/(4xx83xx10^-2)`

or, n = 100 Hz

Hence frequency of overtones n₁:n₂:n₃: ------ = 1:3:3: i.e., 100, 300, 500, 700 and 900 Hz

So number of possible natural oscillations of air column whose frequencies lie below 1000 are 5.