What is the equivalent capacitance between points A & B?

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The discussion focuses on calculating the equivalent capacitance between points A and B in a circuit with capacitors. Initially, it is proposed that the capacitors are in parallel, leading to an equivalent capacitance of 2C. However, further analysis reveals that the capacitors are actually in series due to a zero potential difference across certain points, resulting in an equivalent capacitance of C/2. The conversation emphasizes understanding the circuit's configuration and the implications of steady-state conditions on current flow. Ultimately, the correct interpretation of the circuit leads to the conclusion that the capacitors on the left are in series.
Kronos
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Homework Statement


Find the equivalent capacitance between points A & B

1.png

Homework Equations



Ceq1 = C + C
1/Ceq2 = 1/2C + 1/2C + ...

The Attempt at a Solution


[/B]
It is my understanding that each capacitor top and bottom are connected in parallel, so their equivalent is 2C.

2.png

Now, they are all connected in series, so their equivalent would be:
1/Ceq2 = 1/2C + 1/2C + 1/2C + 1/2C

Thus,
Ceq2 = C/2

Is my reasoning acceptable?
Thank you.
 
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Kronos said:
each capacitor top and bottom are connected in parallel
If the effective capacitance sought were between the left hand side and the right hand side, that would work. But it isn't.

Is there more context here, like an applied varying potential?
If not, think about potentials. What might the potential difference be between the right hand side of the top left capacitor and the right hand side of the bottom left capacitor?
 
The potential difference would just be zero since the capacitors are at steady state. Thus, there is no current flowing through the wire w/ resistor, and by Ohm's law:
V = I*R
V = (0) * R
V = 0
 
Kronos said:
The potential difference would just be zero since the capacitors are at steady state. Thus, there is no current flowing through the wire w/ resistor, and by Ohm's law:
V = I*R
V = (0) * R
V = 0
Right. Does that help you simplify the circuit?
 
haruspex said:
Right. Does that help you simplify the circuit?
Yes. That means that the capacitor on the top left and the capacitor on the bottom left are connected in series, correct? Since the same charge will flow through them.
 
Kronos said:
Yes. That means that the capacitor on the top left and the capacitor on the bottom left are connected in series, correct? Since the same charge will flow through them.
That's how I read it.
 
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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