Q.15.17 A pipe long is closed at one end. Which harmonic mode of the pipe is resonantly excited by a source? Will the same source be in resonance with the pipe if both ends are open? (speed of sound in air is ).
Let the nth harmonic mode of the pipe get resonantly excited by a 430 Hz source.
The pipe resonates with a 430 Hz source in the fundamental mode when one end is open.
Let the mth harmonic mode of the pipe get resonantly excited by a 430 Hz source when both ends are open.
Since m is coming out to be less than 1 the same source will not be in resonance with the pipe if both ends are open.