A) 4
B) 13
C) 6
D) 9
Correct Answer: C
Solution :
Key Idea: A closed pipe produces only odd harmonics. The frequency of note emitted from the pipe for v being velocity of sound in air, is \[f=n\left( \frac{v}{4l} \right)\] and I is length of pipe. \[f=n\times \] fundamental frequency \[\therefore \] We know that human ear can hear frequencies up to 20,000 Hz, hence \[20,000=n\times 1500\] \[\Rightarrow \] \[n=\frac{20,000}{1500}\approx 13\] Maximum possible harmonics obtained are \[1,3,5,7,9,11,13\] Hence, man can hear up to 13th harmonic \[=7-1=6\] So, number of overtones heard = 6 Note: First overtone of the closed pipe is called the third harmonic.You need to login to perform this action.
You will be redirected in
3 sec