The three lowest resonant frequencies of a system are 50 Hz, 150 Hz, and 250 Hz. The system could be
A) a tube of air closed at both ends.
B) a tube of air open at one end.
C) a tube of air open at both ends.
D) a vibrating string with fixed ends.

Question

Quizplus · Accepted Answer

For a tube of air open at one end, the resonant frequencies are odd multiples of the fundamental frequency. Given the frequencies 50 Hz, 150 Hz, and 250 Hz, they fit this pattern (1st, 3rd, and 5th harmonics), which is characteristic of a tube open at one end.

The Three Lowest Resonant Frequencies of a System Are 50