How Do You Calculate the Charge on a Capacitor in This Circuit?

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SUMMARY

The discussion focuses on calculating the charge on a capacitor in a specific circuit configuration involving resistors and a power supply. The circuit includes three resistors (R1 = 13000 Ω, R2 = 18000 Ω, R3 = 2000 Ω) and a capacitor (C = 1.0E-5 F) with a voltage supply of 8.1 V. The user successfully calculated the current through R1 and R2 using Ohm's Law (I = V/R) but encountered difficulties in determining the charge on the capacitor. The charge can be calculated using the formula Q = C * V, where Q is the charge, C is the capacitance, and V is the voltage across the capacitor.

PREREQUISITES
  • Understanding of Ohm's Law (I = V/R)
  • Knowledge of capacitor charge formula (Q = C * V)
  • Familiarity with series and parallel circuit configurations
  • Basic concepts of electrical circuits and components
NEXT STEPS
  • Research the relationship between voltage, charge, and capacitance in capacitors
  • Learn about series and parallel resistor combinations and their effects on circuit behavior
  • Study the transient response of capacitors in RC circuits
  • Explore simulation tools like LTspice for visualizing circuit behavior
USEFUL FOR

This discussion is beneficial for physics students, electrical engineering students, and anyone seeking to understand capacitor behavior in circuits, particularly in the context of charging and current flow analysis.

ksm11b
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I was given this problem through WebAssign for my physics class:
I am given an image of a power supply, followed by a circuit, a resistor1, then it breaks in two paths, one leading to another resistor2 and the other leading to a capacitor and then another resistor3, then the two paths come together and meet back at the power supply.
For each of these I am given the values:
R1=13000 [itex]\Omega[/itex]
R2=18000 [itex]\Omega[/itex]
R3=2000 [itex]\Omega[/itex]
dV=8.1 V
Capacitor=1.0E-5 F

The first part of the question asked for me to find the current in each of the resistors, which was fairly simple.
To do this, I used the formula:
I=V/R
to get 261 [itex]\mu[/itex]A for the first and second resistors, and 0 for the thirds, as when the switch was thrown, the capacitor had to charge and no current reached that resistor.
Now, I am completely lost as to how to find the charge on the capacitor. I have searched for methods, and have only managed to confuse myself even more. I do not know what formula to use. If I did, this would be much, much easier. Can anyone help me?
Attached is a file containing the exact problem copied to microsoft word. Any assistance you can offer will be greatly appreciated!
 
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The attachment didn't go through! I'm sorry guys, I'm not sure what happened. :(
 

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