question_answer

If fundamental frequency of closed pipe is 50 Hz, then frequency of second overtone is:

A) 100 Hz                                  

B) 50 Hz

C) 250 Hz                                  

D) 150 Hz

Correct Answer: C

Solution :

Key Idea: A closed pipe produces only odd harmonics ie., 1: 3 : 5 : 7............... If v is the velocity of sound in air, n is the frequency of note emitted and I is the length of pipe then \[n=\frac{v}{4l}\] Also a closed pipe produces only odd harmonics i.e., 1:3:5:7.......... Hence, second overtone or fifth harmonic frequency is \[=\frac{5v}{4l}=5\times 50=250\,\text{Hz}\]