Question

The fundamental frequency of an air column is a pipe closed at one end is 100 Hz. If the same pipe is open at both the ends, the frequencies produced in Hz are ______.

Options

• 100, 200, 300, 400... 

• 100, 300, 500, 700...

• 200, 300, 400, 500...

• 200, 400, 600, 800

Answer 1

The fundamental frequency of an air column is a pipe closed at one end is 100 Hz. If the same pipe is open at both the ends, the frequencies produced in Hz are 200, 400, 600, 800.

Explanation:

Fundamental frequency, for a closed pipe

v₁ = `"V"/(4"L")` = 100 Hz

Fundamental frequency, for an open pipe

v₁ = `"V"/(2"L")` = 200 Hz

In a pipe open at both the ends, all multiples of the fundamental frequency are produced.

∴ 1 × 200, 2 × 200, 3 × 200...

i.e., 200, 400, 600...