Skip to main content

Waves in Pipes and Strings

 Waves in Pipes and Strings: 

Organ Pipe:  

A hollow tube which is used to produce sound by blowing air into it is called an organ pipe.  It is wind instrument. There are two types of organ pipe which are as follows. 

1. Closed Organ Pipe: The organ pipes whose one end is closed and another end is open  is called a closed organ pipe. e.g. whistle, cap of pen, bottle, resonance tube etc. 2. Open Organ Pipe: The organ pipe whose both ends are open are called open organ  pipe. e.g. flute, clarinet etc.  

Stationary Waves in Closed Organ Pipe 

When a blast of air is blown into the closed organ pipe through its open-end, longitudinal  wave travels forward and gets reflected from the closed end. Due to superposition between  ongoing and reflected waves longitudinal stationary wave is formed in the pipe. There is  always a node at the closed end and an anti node at the open end. The lowest possible  frequency of vibration in the organ pipe is called fundamental frequency and higher  frequencies are called overtones. The various modes of vibration in closed organ pipes are  as follows. 

Fundamental Mode: 

L

In the simplest mode of vibration, called fundamental mode in closed organ pipe, there is a  node at closed end and an anti node at the open end. If λ1 be the wavelength of wave in the  mode, then length L of the pipe can be expressed as 

 L=λ14

 ⟹ λ1 = 4L 

Then, frequency of vibration in this mode is given by 

f1=vλ1, where v is wave velocity or velocity of sound 

∴f1=v4L  

This is the expression for fundamental frequency in closed organ pipe called first harmonic.
Labels:
Location: Nepal

Comments

Post a Comment

Popular posts from this blog

Physics: Simple Harmonic Motion - SHM

Simple Harmonic Motion(SHM) What is Periodic motion? The motion which repeats itself after equal intervals of time is called periodic motion . For example: the motion of planets and satellites, vibration of springs, motion of pendulum, motion of different hands in watch etc. What is Simple Harmonic Motion? The periodic motion in which particle moves to and fro (back and forth) such that the acceleration of the particle is directly proportional to the displacement from mean position and directed towards the mean position is called simple harmonic motion. i.e. for SHM, a ∝ y ( where y is the displacement from mean position) or, a = −ky ..........................(i) (Where, k is proportionality constant. Negative sign shows that the acceleration opposes the displacement from mean position.) SHM in terms of uniform circular motion(Characteristics of SHM): Equation of SHM: Consider a particle moving in a circular orbit having centre at O and radius r with uniform angular velocity ω. Let P...
1 comment
Read more

Exploring Doppler's Effect: How Sound Waves Change Frequency

Exploring Doppler's Effect: How Sound Waves Change Frequency Table of Contents What is Doppler’s Effect? A. Source in motion and observer at rest: a. Source moving towards the observer: b. Source moving away from the observer: B. Observer in motion and source at rest: a. Observer moving towards the source: b. Observer moving away from the source: C. Source and observer both are in motion: a. Source and observer approaching each other: b. Source and observer receding each other: c. Source leading the observer: d. Observer leading the source: Doppler’s Effect summarization Doppler’s red shift: Limitations of Doppler’s effect: What is Doppler’s Effect? When there is a relative motion between the source of a sound and observer, the frequency or pitch of the sound received by the observer is different than the actual frequency or pitch. This phenomenon is called Doppler’s effect. The apparent change in pitch or the frequency of sound due to relative motion between source of sound and ob...
Post a Comment
Read more

The Heritage of Words - The Lamentation of the Old Pensioner - Summary - Grade XII

 The poem "The Lamentation of the Old Pensioner" was composed by an Irish poet and dramatist W.B. Yeats. The speaker of the poem "The Lamentation of the Old Pensioner" is a retired old man who expresses his feeling of sadness and disappointment of having the beauty and youth robbed by the tyranny of time. This poem also contrasts the old and present age of the poet. The poet has felt that time is omnipotent and nobody can resist it. Everyone has to go through various stages of life. Old people are not a burden, rather they are the sources of experience, knowledge, and guidance. The speaker implies that we shouldn't regret as we grow old but celebrate old age. The speaker is sitting under a broken tree while taking shelter under a broken tree. He feels that he is like that broken tree. When the tree was young and beautiful, everybody came and sat under it, but now when it is broken, it's felt alone. In the first stanza, the speaker compares his energetic and ...
Post a Comment
Read more