The circuit is (10K ohm resistor in parallel with unknown Capacitor) which are in series with a 4.7k ohm resistor and a 0.1microF capacitor. V_in is applied over the entire circuit and V_out is taken over the 4.7k ohms and 0.1microF.(adsbygoogle = window.adsbygoogle || []).push({});

So here is the question.

In the circuit, H(s)=V_out(s)/V_in(s)(transfer function I imagine). It is a known that this ratio H(s) is independent of frequency. In other words, H(s) is simply a constant. Find The value of the unknown Capacitor in microfarads if all components are ideal.

My current thinking is that since H(s) is just a constant and not a function of frequency, there is no phase difference between V_in and V_0. I then assumed DC must be applied. If this is true then the Caps are charged and no current is flowing. Therefore, the circuit simplifies to the unknown Cap in series with the 0.1microF. Then by using Q=CV, I found unknown C=(V_out/(V_in-V_out))*0.1microF.

If you find any flaw in my thinking please point it out to me. Also if you want a picture of the circuit please email me at cq2120-forums@yahoo.com.

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# RC circuit question

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