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9277 #81

Posted: Fri Apr 01, 2011 6:03 pm
by wenyang
In the RLC circuit with a driver, I first find a relation between the amplitude and the frequency. Then I take derivative and find the frequency equals to (D) when amplitude is maximized. But ETS gives (C). Anyone knows why?

Re: 9277 #81

Posted: Fri Apr 01, 2011 6:12 pm
by t2kburl
They are asking for a maximum steady state current amplitude. That implies it has settled to a "natural frequency" or resonance.

Here ... let wikipedia explain it ...
http://en.wikipedia.org/wiki/RLC_circuit

Re: 9277 #81

Posted: Fri Apr 01, 2011 6:13 pm
by WhoaNonstop
wenyang wrote:In the RLC circuit with a driver, I first find a relation between the amplitude and the frequency. Then I take derivative and find the frequency equals to (D) when amplitude is maximized. But ETS gives (C). Anyone knows why?
What nationality is this driver?

-Riley

Re: 9277 #81

Posted: Fri Apr 01, 2011 6:15 pm
by tady
WhoaNonstop wrote:
wenyang wrote:In the RLC circuit with a driver, I first find a relation between the amplitude and the frequency. Then I take derivative and find the frequency equals to (D) when amplitude is maximized. But ETS gives (C). Anyone knows why?
What nationality is this driver?

-Riley
"Step bee-hine my yerrow rine." (San-Francisco bus driver, c. 2011)

Re: 9277 #81

Posted: Fri Apr 01, 2011 8:24 pm
by wenyang
WhoaNonstop wrote:
wenyang wrote:In the RLC circuit with a driver, I first find a relation between the amplitude and the frequency. Then I take derivative and find the frequency equals to (D) when amplitude is maximized. But ETS gives (C). Anyone knows why?
What nationality is this driver?

-Riley
I am sorry? The driver is just oscillating potential. However, if you are asking literally what nationality is the driver? I have no idea, maybe made in Japan or Germany? lol

Re: 9277 #81

Posted: Fri Apr 01, 2011 8:27 pm
by wenyang
t2kburl wrote:They are asking for a maximum steady state current amplitude. That implies it has settled to a "natural frequency" or resonance.

Here ... let wikipedia explain it ...
http://en.wikipedia.org/wiki/RLC_circuit
Man, the thing is that I derive the formula and it is (D). If it is (C), then it seems that the resistance has no effect of the amplitude, which is not true. The resistance acts as a damping factor. I bet ETS is wrong.

Re: 9277 #81

Posted: Fri Apr 01, 2011 9:07 pm
by t2kburl
R is a constant