Hey everyone,

I am doing a course in electronic engineering and I've been stuck on this for days, I have linked a picture elaborating what the circuit is, here is all the information I was given to complete this :

Vr = 11,3V with angle of 0 degrees
Vc = 18.2V with angle of -90 degrees
R1 = 2k ohms
C1 = 47 nF

So with the voltages of both the resistor and capacitor I simply added the two(as a vector) which gave me 21.4V with angle of -58 for the source, therefore:

Source = 21.4V with angle of -58 degrees

Now I am meant to find the frequency of this circuit which I just found the source voltage for, I know that f = 1 / (2)(3.14)(C)(Xc) But as far as I know (Xc) can only be found if you have (omega) which needs the frequency to be solved.

Is there a way to find Xc without the frequency? if anybody has a different method of solving this could you share it with me, any help would be really appreciated, thank you.

 

But you know the voltage drop across the resistor. So, you know the current in a series circuit. And you can find the total impedance.

 

I fully understand what you are saying, this would give me 5.65 mA would this be correct? I just don't know where to proceed afterwards, I thought the impedance was found using the Xc, what formula are you referring to?

 

You are focusing on finding an equation to plug things into when you need to be understanding the concepts so that you can come up with the formulas you need based on that understanding.

What is the relationship between the voltage across a device and the current through a device in terms of the impedance?

 

I know what the ohm's law is but this isn't the problem although, I've divided circuit voltage by the current and got 3787 ohms as impedance, my problem persists however, how am I meant to find the frequency with this, I understand you are saying that I should understand the basics first put I can't just pull a formula like that, there were no formulas given for this.

 

Do you know the formula for the impedance Z in a series circuit?

 

Do you know what vector addition is ?

Les.

 

I know what the ohm's law is but this isn't the problem although, I've divided circuit voltage by the current and got 3787 ohms as impedance, my problem persists however, how am I meant to find the frequency with this, I understand you are saying that I should understand the basics first put I can't just pull a formula like that, there were no formulas given for this.

So you've never been exposed to the relationship between capacitance and the impedance and/or capacitive reactance of that capacitor at a particular frequency?

You seem to be operating at a level comparable to if you are given A = πR² that you can find the area of a circle given the radius, but that if you were given the area you couldn't find the radius because no one's give you the formula for that.

 

You know Xc from the current through the capacitor is the same as the resistor, so transpose the formula >>

6.284*F*C= 1/Xc

 

Thank you dodgydave