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Resonance frequency

  1. Dec 24, 2006 #1
    resonance frequency!!!!!!!

    what is meant by resonance frequency ????? i really can't get it.
    if anyone could help i will be gratefull.
  2. jcsd
  3. Dec 26, 2006 #2
  4. Dec 26, 2006 #3
  5. May 18, 2009 #4
    Re: resonance frequency!!!!!!!

    Resonance occurs in an a.c circuit when the frequency of the applied voltage is equal to the natural frequency of the circuit. o:)
    At this frequency; the applied voltage and current are in phase;:wink: the current impedance is purely resistive :cool:and the power dissipated is either a maximum or a minimum.:smile:
  6. May 18, 2009 #5
    Re: resonance frequency!!!!!!!

    yups xhatemx, i believe you are right about the equation. :approve:It must be noted that series resonance os also known as voltage resonance. o:)L/RC is the dynamic impedance. The quality or Q factor can be found by finding the ratio of the current through coil to that of the line current. Or simply using Q= wL/R.:cool:
  7. May 18, 2009 #6
    Re: resonance frequency!!!!!!!

    See my post in the thread "finding resonant frequency" for example of frequency sweep across an L C resonant circuit in Classical Physics Forum.
  8. May 19, 2009 #7


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    Re: resonance frequency!!!!!!!

    what is meant by resonance frequency ?????

    I guess you are not asking for formulas or maths here.

    If you put a coil and a capacitor either in series with one another, or across each other (parallel), and then check them at different frequencies, at one frequency there will be a change in response.

    If the components are in series, and you apply a sinewave to the combination, there will be a very big increase in signal at the junction of the coil and capacitor at one frequency.
    This voltage is a sinewave and at the same frequency as the input sinewave but it can be a lot bigger than the incoming voltage in amplitude (especially if you put a small resistor across the signal generator).

    If they are in parallel and you apply a signal, at all frequencies except one frequency, the signal will be reduced (especially if you put a resistor in series with the coil and capacitor ) , but at that one frequency the signal will (almost) not be attenuated.

    In each case, this one special frequency is called the resonant frequency of the tuned circuit. "Tuned circuit" is the name for a coil and capacitor being used together like this.

    This effect is very important because it can be used to select one frequency and reject all others. This lets you listen to one radio station or watch one TV program instead of all of them at once.
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