Questions tagged [resonance]

Resonance is a characteristic of physical systems having a structure that allows energy to flow between various states at a specific, oscillatory rate (resonant frequency). For a stable resonant system at steady state the internal energy is either fixed without losses or the rate of energy input is equal to the energy losses.

Filter by
Sorted by
Tagged with
2
votes
1answer
447 views

Why don't transformers have capacitors?

I recently learnt about how resonance in an LC (inductor capacitor) circuit could increase the efficiency of the circuit, for application in something like Resonant Inductive Power Transfer. Excuse ...
1
vote
1answer
123 views

Feshbach resonance and the Gross-Pitaevskii equation

I have a question about Feshbach resonance and the (generalized) Gross-Pitaevskii equation. If we consider a BEC at a finite temperature $T_{BEC}$ and a static mean-field thermal cloud at temperature $...
2
votes
1answer
156 views

Relation between shapes and vibrations

I have observed the following shape on surface of water when the bottle was standing on a cooling water machine. I was amazed by the formation because I had not seen this before. I'm not completely ...
1
vote
2answers
129 views

What does resonant frequency in the Q factor mean?

For the Q factor of a body undergoing force oscillations, does resonant frequency refers to the frequency of driving frequency or the body's natural frequency? The term resonant frequency seems to ...
4
votes
2answers
121 views

Musical Instrument that Exhibits Spherical Harmonics

A guitar string exhibits standing wave patterns when its struck, some superposition of sines and cosines, a drum head exhibits a superposition of Bessel functions when its struck. Is there any ...
2
votes
1answer
4k views

Why are there only odd numbered harmonics in one closed end resonant tube? [closed]

Why do we only have odd numbered harmonics at one-end closed tubes, however, if we do a frequency spectrum we have some periodic spikes between the odd harmonic spikes, just like the picture below ...
2
votes
1answer
291 views

Why is the Laplace Transform essentially never used when dealing with problems involving resonance?

Both the Laplace Transform and the Fourier Transform can be applied to a PDE, for example the wave equation, and used to derive a solution to the equation. But I never see the Laplace Transform used ...
3
votes
1answer
493 views

Resonances in QFT

I am a bit confused about resonances in QFT. I am reading Schwarz's QFT book and as far as I understand, if in a reaction the mass of the particle acting as a propagator is bigger than the sum of the ...
0
votes
1answer
628 views

Quantum tunneling/transmission through an infinite potential

In Shankar exercise 5.4.2 we consider the reflection and transmission of a wavefunction through a delta potential $V(x) = aV_0\delta(x)$. I understand that to mean that the potential is zero ...
1
vote
2answers
89 views

What is a correct loudspeaker connecting scheme and why? [closed]

Thinking of "what would be best shape for a subwoofer box?" i came to idea of a barrel, with its sides (or covers) "replaced" with speakers: I have stereo bass amplifier which is fed from single ...
0
votes
2answers
2k views

Why does the length of a pendulum cause different natural frequencies of pendulums in Barton's pendulum?

In Barton's pendulum, the pendulum with string that is the same length, L, as the brass bob (source of driving frequency) has natural frequency equals to the bob's driving frequency. The pendulum ...
0
votes
1answer
122 views

Why is $Q$ factor an important quantity for electrical oscillations transmitting radio waves?

My textbook says that "$Q$ factor is an especially important quantity for electrical ossicilations trasnmitting radio waves. When selecting radio and television stations it is essential that the ...
2
votes
0answers
24 views

What are the conditions for molecular,photon resonance other than same frequency?

I know that the basic condition for molecular,photon resonance is same frequency but what are the other condition for this process like phase relationship,round trip of the molecules and so.Also can ...
2
votes
1answer
80 views

Uncertainty cannot be calculated?

I'm doing an experiment on resonance. The phase difference between the driving force and the one oscillating is given by $$\varphi=\arcsin\left(\frac{y_1}{y_2}\right)$$ where $y_1$ and $y_2$ are ...
5
votes
1answer
433 views

Dispersive regime and resonator frequency pull

I have come across terms such as "dispersive regime" and "dispersive measurement" often. To understand this, I have been reading this, this, and this. In the first paper, the gist I got is the ...
1
vote
2answers
796 views

Does the resonance frequency of a cantilever beam depend on whether it is bending in-plane?

What is the in-plane resonance frequency equation for a single-beam cantilever of rectangular cross-section that is fixed on one end and has a mass M attached to the other end? Below are the only ...
2
votes
3answers
1k views

What is a complex phase shift?

In a complex methods course I am taking, we were given an equation for a particular driven harmonic oscillator where the driving force is trigonometric. I have worked out the math and obtained an ...
0
votes
2answers
971 views

What is the difference between natural, fundamental, resonant, and forced frequencies?

I'm just overall slightly confused on their exact definitions, as they get thrown around a lot.
0
votes
4answers
385 views

How LC oscillator is used for generating signals?

I have been trying to understand some practical applications of LC oscialltors and I dont seem to find much information available on net. One consistent application that I see is "LC circuits are used ...
4
votes
3answers
306 views

What happens in an organ pipe at frequencies other than the harmonics?

I learned that, at frequencies corresponding to harmonics, standing waves are formed. But what actually happens at other frequencies? Won't the reflected wave superimpose with the original wave? Do ...
0
votes
1answer
966 views

What is the effect of mass on resonance amplitude?

When a system is undergoing forced oscillations, why does reducing the mass of the system cause the frequency response curve to shift downwards? I encountered this problem in a practice paper, but I ...
1
vote
1answer
421 views

Can vibrations be used to reduce friction?

This lecture by Julius Miller got me wondering if acoustic resonance (or vibration in general) can be used to reduce friction (or stiction). The answer seems to be no based on the observation that my ...
3
votes
2answers
588 views

How does a driving frequency induce resonance if it is not exactly equal to the natural frequency?

To my understanding when the driving frequency is equal to the natural/resonant frequency of the object, there is constructive interference between the oscillations of the object and driving force. ...
0
votes
2answers
143 views

Are resonances formed in scattering between a baryon and meson?

Consider the following reaction of strong interaction (in a scattering process) $$n+\pi^+\to \Lambda_0+K^+\tag{1}$$ Then the particle $\Lambda_0$ formed decays with weak interaction $$\Lambda_0\to ...
1
vote
1answer
415 views

What is the relationship between excitation and resonance?

From Resonance (particle physics) - Wikipedia: In particle physics, a resonance is the peak located around a certain energy found in differential cross sections of scattering experiments. These ...
-1
votes
1answer
150 views

Time evolution of state in rotating $B$-field spin system

I'm given a state $|\psi(t)\rangle$ that solves the time dependent Schroedinger equation with the Hamilton operator $\hat{H}(t)$. $\hat{H}(t)$ describes a Spin-$\frac{1}{2}$ in a rotating magnetic ...
1
vote
0answers
125 views

What is the mathematical basis behind using a chirp signal to determine the resonant frequency of a second order differential system?

It is a common practise for engineers to try to determine the resonant frequency of a system through a chirp signal. Given a damped oscillating system with displacement $x$, driven by a chirp signal ...
1
vote
0answers
522 views

How is sound produced in pea whistles? (I think they're called police whistles in the US.)

I read the topic called 'Whistle Physics' on this forum. From what I gathered there, @alephzero seemed to be saying that changes in air pressure cause air to be alternately sucked in and pushed out of ...
2
votes
1answer
213 views

Why are the nodes of an open tubular bell located at .224*L instead of .25*L?

Say that we have a tube of length $L$. In the tube, there is a standing wave of wavelength $\lambda$. Then, $L=\lambda$. $\hspace{2.5cm}$ In the above diagram, the wave's amplitude is highest at ...
1
vote
1answer
130 views

Resonance and modes

I use a metal body (let's say cooking pot) in which I induce eddy current via induction at certain frequency which I can change as I wish. Every object has it's own accustic resonant frequency. If ...
1
vote
0answers
109 views

Air flow through a penny whistle

I am confused about exactly how air flows through a penny whistle. I would also like to double check that I understand correctly what the cavity of resonance is. Say I have a whistle like this: <...
1
vote
0answers
70 views

Measuring time in the photoelectric effect

Consider the following hypothetical: An atom is traveling with a velocity of v to the left, directly towards an incoming photon, as crudely depicted below. p----> <----A Question (1): What is ...
2
votes
5answers
769 views

What is the geometry of DeBroglie standing waves?

I asked a similar question here . But never received a complete answer. So I've made the question more specific to DeBroglie waves. So from what I've read DeBroglie waves are indeed standing waves ...
1
vote
0answers
201 views

What 2d shapes would have the most resonant frequencies?

A square Chladni plate has a handful of resonant frequencies in the audio range. If you wanted to make a plate with very many (infinite?) resonant frequencies, what shape would be best? You wouldn't ...
1
vote
1answer
472 views

Designing a high-$Q$ RLC circuit

I would like to make a series RLC circuit which will serve as RF receiver. I would like very high frequency selectivity, i.e. narrow bandwidth, i.e. $\pm$200 Hz. The sharpness of a resonance is ...
0
votes
1answer
91 views

Is my understanding of standing wave resonance satisfactory in this exercise?

As the title suggests, I'm wondering how I handled the following exercise checks out: A loudspeaker is placed close to one end of a pipe that is open at both ends. The loudspeaker is driven by a ...
2
votes
1answer
58 views

What are all the possible ways to achieve acoustic resonance in a cavity?

If one were to observe acoustic resonance in a cavity (semi-closed volume of space) what is the complete list of potential hypotheses as to the cause? In my limited experience I can list the ...
2
votes
1answer
211 views

The Helmholtz resonator, what's actually resonating?

I'm trying to more closely understand the physical mechanism behind the Helmholtz resonator. If I model the resonator in terms of an analogous series linear electrical circuit: resistance ($R$), ...
5
votes
4answers
5k views

Is there a resonance frequency to air itself?

Obviously a lot of things cause air to vibrate, but does air have an actual resonance frequency?
1
vote
1answer
119 views

How to reconcile infinite cross section of resonances with cross section formula from quantum mechanics?

If we consider $s$-wave scattering for two scalar fields $\phi$ and $\chi$ with an interaction $\frac{g}{2}\phi^2\chi$, then the Lorentz-invariant scattering amplitude to second order is: $\mathcal{M}...
7
votes
1answer
247 views

Air oscillation at open window of a moving car

When driving a car with an open window one can hear (and feel) oscillations of air at the threshold of the open window. I used to think the open window and the car interior were forming a Helmholtz ...
1
vote
1answer
477 views

mode-locked laser Repetition Rate

I don't understand how we can produce a laser system with different (lower) repetition rate than the resonant frequency of the cavity? In other words, when we have different resonating modes, then ...
2
votes
1answer
887 views

The “watering hole” frequency versus microwave oven frequency

I recently learned about the "watering hole," a group of frequencies between 1.42 and 1.66 GHz. I also read that microwave ovens operate at 2.4 GHz. If 21 to 18 cm (1.42 to 1.66 GHz) is the resonant ...
2
votes
1answer
64 views

Renormalising $\Delta$ baryon mass in chiral effective field theory

I have essentially no experience of quantum field theory, other than a superficial knowledge of some basic ideas - my apologies if I've phrased anything unusually or made any mistakes in my question ...
1
vote
1answer
1k views

Why do piezoelectric elements have a resonant frequency?

While working with a piezoelectric element, I noticed some high frequency oscillations at 6kHz. I can't figure out why the piezo element has a resonant frequency. This is unlikely to be noise as there ...
0
votes
1answer
31 views

In mechanical systems, it is easier to understand concept of natural frequency, could somebody explain natural frequency in electronic elements?

In mechanical systems, natural frequency simply means the frequency at which the body will oscillate when it is disturbed(assuming the body will suffer zero resistance in motion) but wihle studying ...
1
vote
2answers
194 views

Has anyone driven a bell or tuning fork using light?

In principle a metal bell or tuning fork of sufficiently high quality factor could be driven by audio frequency radio waves of sufficient power to produce an audible hum. Has this been done, yet? If ...
4
votes
0answers
500 views

How do I calculate the resonance frequency of a block of material?

I would like to know how I go about calculating the resonance frequency for an object, given its material properties and dimensions. For example, a small rectangle $X$ by $Y$ by $Z$ dimensions, I ...
0
votes
1answer
133 views

Finding the resonant frequency of a rectangular resonator filled with a magnetic material

The prompt is to find the resonant frequency $f_r$ of a rectangular resonator which is filled with a magnetic material rather than standard air or vacuum. I'm confused as how the resonance frequency ...
0
votes
2answers
897 views

How to determine resonance frequency of RLC circuit empirically?

I have a series RLC circuit and I can find its theoretical resonance frequency. However, I would like to verify this value through testing. How can I find the resonant frequency? The tools I have are ...

1
3 4
5
6 7
13