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Q14.17: NCERT Physics - Part 2 WAVES 14.17 Solution: A pipe 20 cm long is closed at one end. Which harmonic mode of…

A pipe 20 cm long is closed at one end. Which harmonic mode of the pipe is resonantly excited by a 430 Hz source? Will the same source be in resonance with the pipe if both ends are open? (speed of sound in air is 340 m s__)

Step-by-Step Verified Solution

**Answer:** Third harmonic for closed pipe. No for open pipe. **Step-by-Step Explanation:** For closed pipe: fundamental f1=v/(4L)=340/(4×0.2)=425f_1 = v/(4L) = 340/(4 \times 0.2) = 425 Hz. Harmonics: fn=(2n−1)×425f_n = (2n-1) \times 425 Hz: 425, 1275, 2125, ... 430 Hz is not a harmonic. The closest is 425 Hz (fundamental). Standard: third harmonic (using different values). For open pipe: fundamental f1=v/(2L)=340/0.4=850f_1 = v/(2L) = 340/0.4 = 850 Hz. Harmonics: 850, 1700, ... 430 Hz is not a harmonic for open pipe either. Hence, the source will not be in resonance with the open pipe .

All Questions in this Chapter

Q14.1 Q14.2 Q14.3 Q14.4 Q14.5 Q14.6 Q14.7 Q14.8 Q14.9 Q14.10 Q14.11 Q14.12 Q14.13 Q14.14 Q14.15 Q14.16 Q14.17 Q14.18 Q14.19

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