What is Resonance: Definition and 656 Discussions

Resonance describes the phenomenon of increased amplitude that occurs when the frequency of a periodically applied force (or a Fourier component of it) is equal or close to a natural frequency of the system on which it acts. When an oscillating force is applied at a resonant frequency of a dynamic system, the system will oscillate at a higher amplitude than when the same force is applied at other, non-resonant frequencies.Frequencies at which the response amplitude is a relative maximum are also known as resonant frequencies or resonance frequencies of the system. Small periodic forces that are near a resonant frequency of the system have the ability to produce large amplitude oscillations in the system due to the storage of vibrational energy.
Resonance phenomena occur with all types of vibrations or waves: there is mechanical resonance, acoustic resonance, electromagnetic resonance, nuclear magnetic resonance (NMR), electron spin resonance (ESR) and resonance of quantum wave functions. Resonant systems can be used to generate vibrations of a specific frequency (e.g., musical instruments), or pick out specific frequencies from a complex vibration containing many frequencies (e.g., filters).
The term resonance (from Latin resonantia, 'echo', from resonare, 'resound') originated from the field of acoustics, particularly the sympathetic resonance observed in musical instruments, e.g., when one string starts to vibrate and produce sound after a different one is struck.

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  1. I_am_learning

    Damped Resonance Frequency OF series LCR circuit

    the solution for current I, for series LCR circuit is I = (E/Z)sin(wt+\phi) Where Z = \sqrt{R^2 + (X_{L}-X_{C})^{2}} So for Resonance (i.e. maximum Current Amplitude) of LCR Circuit the necessary condition seems to be X_{L}=X_{C} Which gives \omega=1/\sqrt{LC} But some text-books and wikipaedia...
  2. E

    RLC Circuit Resonance Frequency for WRUF Broadcast

    Homework Statement a) WRUF broadcasts at 103.7 MHz, what is the wavelength associated? b) If you were to use an RLC circuit to tune to this radio station, what resonance frequency would you tune to? Homework Equations f(resonance)= 1/(2\pi\sqrt{LC}) The Attempt at a Solution a)...
  3. H

    Is This Resonance Structure Valid?

    Is this valid: http://img197.imageshack.us/i/imagecct.jpg/
  4. L

    Neutral-earth harmonic resonance

    When carrying out a system analysis During design stage (Variable speed drives connected to 3 transformers in parallel) is it a normal practise to check/measure neutral - Earth harmonics, can this be predicted?
  5. J

    Sine wave resonance using square wave input

    Hello All, I have been doing a few basic experiments with coils lately and I am trying to figure out the simplest way to drive a coil at its natural resonant frequency so that I can get the Q as high as possible. My only problem is that I don't have a sine wave generator that I can use. I...
  6. R

    What Frequency Excites Resonance in a Two-Mass, Two-Spring System?

    Hi, i am currently working on a problem involving a one dimensional, vertical two mass two spring system where the upper mass is free to move with the lower mass adn the lowermass is excited using an oscillating force. The springs are different with a damping force in the form of D = C*x'...
  7. D

    How Can You Measure Radius Distortion in a Shattered Wineglass Using Resonance?

    Homework Statement We shattered a wineglass using resonance. We also filmed the radius distortions here: http://www.youtube.com/watch?v=HpcXf906wPw&feature=channel_page We also filmed it shattering here: http://www.youtube.com/watch?v=45agipT91Vw&feature=channel How do we measure how...
  8. I

    Resonance frequency of a magnetron cavity

    Is the resonance frequency of a magnetron cavity purely a function of its geometry? Thanks!
  9. M

    Resonance & Tubes: Frequency of Tuning Fork

    Homework Statement An open vertical tube is filled with water and a tuning fork vibrates over its mouth. As the water level is lowered in th etube, resonance is heard when the water level has dropped 17 cm, and again after 49 cm of distance exists from the water to the top of the tube. What is...
  10. J

    Electrical Resonance Problem

    A constant voltage at a frequency of 1MHz is maintained across a circut consisting of the inductor in series with a variable capacitor. When the capacitor is set to 300pF the current has its max value. When the capacitor is reduced to 284pF the current is 0.707 of its ma value. Find The...
  11. J

    Understanding Electrical Resonance in AC Circuits

    Explain the meaning of the term resonance as applied to a series A.C circut. What is the best way of answering this question. I am kind of confused on what to include in the definition and what not to include. We know that the capacitive reactance and the inductive reactance depend...
  12. K

    Measured resonance in RLC -> drawing graphs with Matlab.

    Drawing graphs with errors using Matlab. I'm writing my first serious report, yay!, from the measurements we made with series RLC -circuit. I'm supposed to determine the values of the two coils we used as well as their self-inductanses. We had four different circuits: R, L1 and C in series...
  13. P

    Resonance Curve - Do I have enough info?

    Homework Statement For a sinusoidally driven RLC circuit. Draw accurate resonance curves for C = 0.01uF, L = 0.01mH and i) R = 20 ohm ii) R = 200 ohm 2. The attempt at a solution Believe it or not, I do not have a single example of resonance curves in any of my textbooks...
  14. Q

    Feshbach Resonance: Links, Articles, Books for Applications

    Could you recommend me some good links/articles/bookz on subj and its applications?
  15. L

    Uncovering Resonance Frequency in Wine Glasses

    Hey guys, Homework Statement I am conducting an investigation in which we will be playing around with the resonance of different wine glasses. I would like to know what characteristics of wine glasses cause the resonate frequency to change. Preferably not a direct answer but more a hint...
  16. F

    Resonance in Closed air columns

    is is based on the experiment where we had to find the point in which tuning fork forces air inside open-ended air column into resonance, the length of the tube is altered by changing the water level in the tube. the water level can be altered by raising or lowering a reservoir of water, thus...
  17. K

    Resonance Vibrations Homework: Find RPM

    Homework Statement A front-loading washing machine is mounted on a thick rubber pad that acts like a spring; the weight W = mg (with g = 9.8 m/s^2) of the machine depresses the pad exactly 0.19 cm. When its rotor spins at ω radians per second, the rotor exerts a vertical force F0=cos(ω*theta)...
  18. D

    Electron spin resonance question

    Homework Statement This isn't exactly a homework question, but my lab partner and I came across a phenomena whilst doing an electron spin resonance experiment, and I was wondering if anyone could help explain it. The sample we found electron spin resonance for is...
  19. P

    Surface Plasmon Resonance in Gold Films: My Conundrum

    I'm trying understand surface plasmon resonance in a gold film, and have decided that gold must have a refractive index of say 5-10ish in optical light. However I'm not sure and I think I might be on the wrong track. Also does negative refractive index have anything to do with surface plasmon...
  20. M

    Wireless power (using resonance induction a.k.a. evanescent waves coupling)

    Hello, I have read a lot of literature in this area and am really confused. I need help. There is a drive today towards increasing the distance over which energy transfer is feasible. Currently, mutual induction is used commercially for a whole bunch of applications, but each of them...
  21. P

    Understanding Benzene: Hybrid Structures vs. Superposition Explained

    Question: Is a hybrid structure and a superposition the same thing? (I'm interested in the case of benzene) Read many sources but they were contradictory.. Please help! Thanks!
  22. C

    Year 12 Sound Problem (Involves resonance in a closed pipe).

    Homework Statement Hi :) This question is from a test i had today. For some stupid reason we get to finish it off tomorrow. I figured i do what everyone else will, and sort out the what i didn't understand. Luckily this was it. Anyway, the question is typed from memory so it may seem a bit odd...
  23. M

    What Defines the Maximum Frequency in Damped Driven Oscillations?

    I am looking at forced vibrations and I have come across this: (w_max)^2 = (w_0)^2 - (1/2)y^2 Now I am not entirely sure of what the (w_max) is. ANd where does this equation come from? It was simply stated without a derivation. THanks guys!:biggrin:
  24. E

    Fulminate Ion: Resonance Struct & Most Important Contributor

    Like the cyanate ion (NCO-), the fulminate ion (CNO-) has three resonance structures. Which is the most important contributor to the resonance hybrid? Suggest a reason fro the instability of fulminate.
  25. M

    How Do You Calculate Impedance in a Resonant RLC Circuit?

    Homework Statement Quick one guys, I am very confused about the impedance of a RLC circuit. Say when you have more than one resistor or more than one capacitor or inductor in different combination, you get a impedance with two parts(imaginary which is the reactive part and the resistive...
  26. M

    How to drive an actuator in its resonance frequency?

    I can give the following description to the problem, but I don't specifically know what should be done to drive an actuator (specially a piezoeelctric one) in its resonance frequency using a feedback. **The sensor consists of a piezoelectric transducer and a vibration pickup. When an...
  27. I

    Modelling wind resonance in turbines (linear)

    Hello! I chose an aspect of a dynamical system exhibiting resonance to model. The focus of the project is on the resonant response of the system. If the wind has a frequency that matches the natural frequency of a turbine, then the turbine will resonate due to wind. I am working on modelling...
  28. B

    Particle resonance and the resonance in a driven, damped classical

    I am trying to understand the analogy between a particle resonance and the resonance in a driven, damped classical oscillator. I guess I should first ask for a clear definition of a particle resonance - is this just an excited state which decays quickly? I understand that the KG equation...
  29. M

    Piezo-electric actuator’s resonance frequency

    Hi all, Sorry for any mistakes but this is my first time I write a post in English. I would like someone to explain me exactly what is the resonance frequency in a piezo-electric actuator. Also give me any link for more information. Does the frequency of the controller play any role...
  30. N

    Standing waves and resonance frequency

    Homework Statement Hi all. I have shown that standing waves occur on a string of length L (fastened at x=0 and x=L) for angular frequencies: \omega_n=n\frac{v\pi}{L}. Are these frequencies the same as the strings resonance frequencies? Thanks in advance. Regards, Niles.
  31. P

    Resonance ans normal modes in an open pipe

    Hello, I have a question about standing sound waves in an open pipe caused by a speaker, I know that normal mode frequencies are given by f_n = n\frac{v}{4L}, \quad n=1,2,3,... if we put a microphone into the pipe, and if the frequency of the speaker is a normal mode frequency, we see...
  32. J

    Resonance in Electrical Circuit

    (a)Find the frequency at which a 33 uF capacitor has the same reactance as a 33 mH inductor. (b) What is the resonance frequency of an LC circuit made with this inductor and capacitor. Well I believe the equation I use is 1 / (2 Pie \sqrt{}LC) but when I use it I come out with a answer very...
  33. G

    What is the Significance of Resonance in Nuclear Magnetic Resonance?

    Nuclear magnetic resonance! Hello all,i was studying about nuclear magnetic resonance,what i came to know is the study of nucleus in presence of magnetic field and then considering the possible states. But sir/madam what i don't understand here is using the word "RESONANCE". What it signifies...
  34. I

    Resonance states and complex energies

    I'm reconsidering the problem of resonance states. We know that the resonances in QM are described as the complex energy poles in the scattering amplitude. In the version of QFT, the resonances are described by the complex mass poles of the scattering matrix. In QFT, I can understand that...
  35. B

    Bell Resonance in Air vs. in Water

    Hi, I am a noob and have a question with respect to resonance. A bell hanging of a string been in Air, when struck, has resonance peak(s) in the audible and possibly ultra sound spectrum. My questions is, if this very same bell would be hanging of a string and fully submerged in water...
  36. S

    Examples of resonance of sound in tubes

    Hello :) We did a lab in class and the lab was about resonance of air columns. We used a tube and filled it with water. Then we held a tuning fork above the tube to see at which points the resonance occurs. If a vibrating fork is held over the open end of the column, the loudness of the sound...
  37. A

    Lewis Structures and Resonance

    1. I need to be able to draw K C2H3O2 and any resonance structures. SO far I have drawn four and I can think of at least four more to draw... does anyone know if there are more than four and if so, could you please submit a pdf of the resonance structures?
  38. N

    Neutron Resonance: Cross Sections in Reaction w/ Targets

    I want to know more about the cross sections in reaction neutron + targets which neutron has energy in the resonance of target. Help me!
  39. C

    Possible Sources of Error in Speed of Sound Lab

    resonance in closed air column Homework Statement we have conduct a lab to determine the speed of sound and estimate room temprature by using open air column method. put a tube in the water, have a tuning folks (sound source) on the above, and pull the tube up and down to find the resonance...
  40. W

    Temperature & Resonance: Exploring Frequency Response

    So this morning, while prepping for my calc 2 final, I sat at the breakfast table and drank my coffee. After stirring in some sugar, I tapped the spoon on the side of the mug to shake off the remaining drops of coffee. I noticed the pitch of resonating spoon was increasing. I wondered about a...
  41. B

    Resonance in tube filled with air

    Homework Statement A long tube contains air at a pressure of 1.00 atm and a temperature of 77.0 degrees celsius. The tube is open at one end and closed at the other by a movable piston. A tuning fork near the open end is vibrating with a frequency of 500 Hz. Resonance is produced when the...
  42. K

    Conducting a Frequency Sweep for Resonance Frequency Determination

    how does one perform a frequency sweep to obtain resonant frequency? for instance, if the inductance is 50mH and the capacitance is 20nF, how do I achieve a resonant frequency of 200khz? what parameters are involved?
  43. S

    What Are the Equations for Nuclear Magnetic Resonance in Water?

    Homework Statement Nuclear magnetic resonance in water is due to the protons of hydrogen. Find the field necessary to produce NMR (nuclear magnetic resonance) at 60 MHz. Homework Equations These are the equations I think I'm supposed to use: omega (subscript zero) = gamma * B...
  44. A

    At resonance, the phase angle in an AC circuit is?

    At resonnance, the phase angle in an a.c circuit is ?pls need an answer. 2. the magnetic force on a charged particle moving with velocity v is ? 3. The current through a resistor in a.c circuit is given as 2 sin wt. Determine the d.c equivalent of the current? 4. What is the angle of dip at...
  45. Simfish

    Where does resonance fundamentally come from?

    I know it has something to do with the natural vibrational states of atomic bonds (but does it also come from other sources?). But where do those natural vibrational states come from? Why do they tend to arise? And what exactly is the physical process through which resonance amplifies...
  46. M

    Calculating Mass Needed for Piano String Resonance at 260 Hz

    Question: On a piano, middle C's 260 Hz. What mass is needed then to suspend from a hanger for resonance at 260 Hz for your string (in the absence of a tuning fork)? Is this sensible? Given: mstring = 0.0003 kg Lstring = 1.809 m (entire length of string) L = 1.370 m (length between fixed...
  47. Q

    Help, RLC Circuit Problem - Peak Current At Resonance

    Homework Statement A 5 Micro-F Capacitor, a 65mH Inductor, and a 10 Ohm resistor are connected in series Find the resonant frequency of this circuit. Determine the peak current at resonance, if the peak voltage is 100V Homework Equations Fr = (1/2Pi) Square Root(1/LC) I don't know...
  48. D

    Engineering Circuit, capacitance, resonance

    Hi all; So the problem goes as follows: For the circuit in the figure, what should be the capacitance C to put the circuit into resonance? What is then the RMS value of the current? What is, then, the peak value of the air-gap flux density? Is, then, the assumption about infinite...
  49. K

    Concept Question about Resonance and Oscillations

    This may sound like a strange question... I was walking away from my physics class today and I wondered if resonant vibrations were the reason my shoelaces become untied. I noticed that when I walk faster, and produce what I believe are more forced oscillations, they become untied more...
  50. B

    Sound Waves, Resonance, and intensity

    "If two flutists play ther instuments together at the same intensity, is the sound twice as loud as that of either flutist playing alone at the intensity? Why or why not?" I know that the answer has something to do with the sensation of loudness being logarithmic in the human ear, but I...
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