Question:medium
An organ pipe 40cm long is open at both ends. The speed of sound in air is 360ms-1 . The frequency of the second harmonic is ____Hz.
An organ pipe 40cm long is open at both ends. The speed of sound in air is 360ms-1 . The frequency of the second harmonic is ____Hz.
Updated On: Feb 20, 2026
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Correct Answer: 900
Solution and Explanation
The frequency of harmonics in an open pipe can be determined using the formula for the nth harmonic: fn = n(v/(2L)), where:
- v is the speed of sound (360 m/s in this case).
- L is the length of the pipe (40 cm = 0.4 m).
- n is the harmonic number.
For the second harmonic (n = 2), the frequency f2 is given by:
f2 = 2(v/(2L)) = v/L
Substitute the given values:
f2 = 360 / 0.4 = 900 Hz
Therefore, the frequency of the second harmonic is 900 Hz. This value lies within the provided range (900,900).
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