Q. The two nearest harmonics of a tube closed at one end and open at other end are 220 Hz and 260 Hz. What is the fundamental frequency of the system ?
A) 10 Hz
B) 20 Hz
C) 30 Hz
D) 40 Hz
Explanation
[Solution] Consecutive (odd) harmonics of a closed pipe differ by $2f_0$: $2f_0 = 40$ Hz, so $f_0 = 20$ Hz. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.