Phase Angle Analysis of RC Circuits

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The discussion focuses on calculating the phase angle between input and output voltages in two RC circuits, where the positions of the resistor and capacitor are switched. The user initially expresses uncertainty about using their calculations to determine the phase relationships. They provide values for the impedances and voltages, leading to a conclusion that in the first circuit, the output voltage leads the input by 38.51 degrees, while in the second circuit, it lags by 51.49 degrees. The user acknowledges their own reasoning and the helpfulness of the forum in clarifying their understanding. Overall, the thread emphasizes the importance of analyzing phase angles in RC circuits.
nhenzie
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Homework Statement



Find the phase angle between the input and output voltages in the following two circuits - in each case state whether the output leads or lags the input voltage.

14twly1.jpg


The second circuit is the same but the capacitor and the resistor are switched around.

Homework Equations


I'm not really sure, this is why I'm here, I don't know how to use the information I have to get the answer.

The Attempt at a Solution



So far I have:

Zr = 1000Ω∠0
Zc = 795.77Ω∠-90
Zt = 1278Ω ∠-38.51
It = 19.562 mA ∠ 38.51
Vr = 19.56v ∠38.51
Vc = 15.57v ∠-51.49
 
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nhenzie said:

Homework Statement



Find the phase angle between the input and output voltages in the following two circuits - in each case state whether the output leads or lags the input voltage.

14twly1.jpg


The second circuit is the same but the capacitor and the resistor are switched around.

Homework Equations


I'm not really sure, this is why I'm here, I don't know how to use the information I have to get the answer.


The Attempt at a Solution



So far I have:

Zr = 1000Ω∠0
Zc = 795.77Ω∠-90
Zt = 1278Ω ∠-38.51
It = 19.562 mA ∠ 38.51
Vr = 19.56v ∠38.51
Vc = 15.57v ∠-51.49

Hi nhenzie, Welcome to Physics Forums.

You've calculated a phase angle in association with Vr. How do you interpret that?
 
Thanks, I've been an avid browser of this forum for help with homework, it's been a great resource so far.

I guess I would say that Vr leads the input voltage by 38.51 degrees, and in the 2nd circuit the output voltage lags the input voltage by 51.48...I'm thinking I just answered the question myself...thanks for the guidance, I should probably think things over a bit more before posting...
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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