Potential difference in multi cell circuit

AI Thread Summary
The discussion centers on calculating the potential difference between two points in a multi-cell circuit involving capacitors. Participants emphasize the importance of applying Kirchhoff's Voltage Law (KVL) correctly, noting that the voltages across capacitors can be expressed as V1 = Q/C1 and V2 = Q/C2. There is a consensus that while the charges on the capacitors may be the same, the voltages need not be equal. A misunderstanding arises regarding the application of KVL, with some confusion about whether the voltages refer to capacitors or batteries. Ultimately, the conclusion suggests that if the voltages sum to zero, it indicates no charge passes through the capacitors, leading to V1 and V2 both being zero.
carlyn medona

Homework Statement


Find potential difference between a and b in the figure

Homework Equations


Q=cv

The Attempt at a Solution

can anybody tell me how to apply the equation in this problem with more than one cell
[/B]
 

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Assuming that neither the batteries or the capacitors have ohmic resistance:

The capacitors are not exactly in series, however what can u say about the (transient) currents ##I_1## through the left capacitor and the current ##I_2## through the right capacitor? Are they equal? Why? And if they are equal what can you infer for the charges ##Q_1## and ##Q_2## of each capacitor?
 
carlyn medona said:

Homework Statement


Find potential difference between a and b in the figure

Homework Equations


Q=cv

The Attempt at a Solution

can anybody tell me how to apply the equation in this problem with more than one cell[/B]
Apply KVL which is potential difference in any close loop is zero
 
So will potential difference between the two capacitors be equal and opposite, and I thought charge through them will be same, not sure, I am not good with multi cell circuits
 
charges will be the same but voltages not necessarily. Apply KVL in the circuit knowing that the voltages at capacitors are ##\frac{Q}{C_1}## and ##\frac{Q}{C_2}##.
 
I applied loop rule and got v1+v2=0
Am I doing something wrong
 
carlyn medona said:
I applied loop rule and got v1+v2=0
Am I doing something wrong

carlyn medona said:
I applied loop rule and got v1+v2=0
Am I doing something wrong[/QUOT
Yes you are not applying loop rule properly
 
Are v1, v2 the voltages of capacitors or of the batteries?
 
Capacitors
 
  • #10
Ok then you are correct. Now replace V1 , V2 with what I said at post 5 and find Q.
 
  • #11
But q is same and c is different and v1 +v2 =0 so is q equal to zero, so no charge pass through capacitor and have v1= v2=0
 
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