I with finding a voltage across a Capacitor

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    Capacitor Voltage
AI Thread Summary
The discussion focuses on calculating the voltage across a capacitor using the Voltage Divider Rule and Thevenin Equivalent in a given circuit. The correct voltage is stated to be 13.61V, but the user struggles to achieve this result despite calculating total current and equivalent resistance. They note that no current flows through the R2 + C1 leg, raising questions about the voltage drop across R2. The consensus is that the voltage across R2 equals the voltage across the capacitor, but the user’s calculations using the voltage divider rule do not yield the expected answer. Clarification on the workings and assumptions in the calculations is requested to resolve the issue.
anonx12

Homework Statement


Find the voltage across the capacitor given the data underneath the circuit.

Homework Equations


Voltage Divider Rule
Thevenin Equivalent
Ohms Law

The Attempt at a Solution


I have tried using the Voltage divider rule but I can't seem to get the right answer. The correct answer is 13.61V . I calculated the total current and overall resistance, but I don't know how to arrive where they got. Can someone help me?
 

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There is no current flowing in the R2 + C1 leg of the circuit so what is the voltage drop across R2 ?
 
Last edited:
I calculated the equivalent resistance of the ones in parallel, excluding R1. That number is 1435 ohms. I then tried to use the voltage divider rule: Vr2= Req/(R8+Req)
 
I think you missed the point of my question . Please show us your actual workings .
 
Nidum said:
I think you missed the point of my question . Please show us your actual workings .
The voltage across resistor 2 is the same as the voltage across the capacitor. Since the voltage across parallel circuits is the same, we only need to use the voltage divider rule among Resistor 1 and the resistors in parallel. Doing this however, doesn't result in the correct answer.
My worked solutions is : Vr2= (Req/(Req+R1))(35V) Vr2=5.32V Req= ((1/2)+(1/8)+(1/14))^-1
 
anonx12 said:
The voltage across resistor 2 is the same as the voltage across the capacitor

That is not correct . If you can work out why then solving the rest of the problem will be easy .
 
In this simpler problem what is V2 ?
RC temp.jpg

nb : Assume that the circuit is in a settled condition .
 
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