Question

An organ pipe closed at one end has a fundamental frequency of 1500Hz. The maximum number of overtones generated by this pipe, which a normal person can hear is?

(a) 12

(b) 9

(c) 6

(d) 4

Answer 1

Right answer is (c) 6

Explanation: Human year can hear frequencies upto 20000Hz. For a closed organ pipe,

v=n×v/4L

=n×fundamental frequency

20000=n×1500

n≅13

The possible harmonics are: 1, 3, 5, 7, 9, 11, 13

Maximum number of overtones=7-1=6.