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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 a signal generator and an oscilloscope.

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    $\begingroup$ Please include a circuit diagram. All circuit questions should include a diagram. In the case of this question, we need to know whether the circuit is series or parallel. $\endgroup$ – DanielSank Jan 9 '18 at 1:58
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Drive the circuit with the signal generator. Vary the frequency and measure the gain of the circuit as a function of frequency. The resonant frequency is an extremum (i.e. a maximum or a minimum, depending on the circuit) on the gain versus frequency plot.

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    $\begingroup$ I'm afraid this answer assumes too much. What is the gain of an arbitrary RLC network? In other words, where is the circuit driven and where is the output taken? Consider, for example, that a parallel RLC network has just two nodes. $\endgroup$ – Alfred Centauri Jan 9 '18 at 2:26
  • $\begingroup$ Typically in that case you would ground one end and do both the measuring and the driving at the other end. Since a real function generator has finite output impedance, you can still measure a gain this way, and that output impedance doesn't change the resonant frequency (so long as it's purely real). In general, it doesn't matter much where you drive and measure it, since an RLC circuit has only one resonant frequency. $\endgroup$ – Chris Jan 9 '18 at 2:39
  • $\begingroup$ in addition, you require a series resistance ahead of the circuit of value ~1000 ohms to prevent current excursions that exceed the source capacity of the generator. Note that this is a well-understood (solved) problem and if posted on the engineering stack exchange you'd get a pile of useful answers. -Niels $\endgroup$ – niels nielsen Jan 9 '18 at 2:50
  • $\begingroup$ Extrema are badly defined quantities, because the derivative at an extremum is horizontal. Experimentally, one tries to avoid finding extrema. $\endgroup$ – Massimo Ortolano Jan 9 '18 at 8:15
  • $\begingroup$ @niels nielsen-You can avoid this problem simply by reducing the voltage of the generator. This can usually be set on the generator. $\endgroup$ – freecharly Jan 9 '18 at 15:30
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If you have a RLC circuit in series, you apply a constant sinus voltage from your generator and measure the sinusoid current through the circuit with your oscilloscope, e.g., by measuring the voltage drop over your resistor. Then you vary the frequency of the generator. You have the resonance frequency when the current amplitude has a maximum.

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