How do I calculate the voltage across each capacitor after the switch is closed?

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SUMMARY

The voltage across each capacitor in the circuit after the switch is closed can be calculated using the equations Q = CV and V = IR. The voltage for the 5 µF capacitor is determined to be 20 V, which is equivalent to the voltage across the 40-ohm resistor due to the steady-state condition in the circuit. For the 10 µF capacitor, the voltage can be derived by analyzing the resistive voltage divider formed by the surrounding resistors once the transient currents have dissipated and the circuit reaches a static state.

PREREQUISITES
  • Understanding of capacitor charging equations (Q = CV, Q = Qo*e^(-t/RC))
  • Knowledge of Ohm's Law (V = IR)
  • Familiarity with DC circuit analysis and steady-state conditions
  • Ability to identify and analyze resistive voltage dividers
NEXT STEPS
  • Study the concept of steady-state behavior in DC circuits
  • Learn about resistive voltage dividers and their applications
  • Explore capacitor discharge equations and time constants
  • Practice problems involving multiple capacitors in series and parallel configurations
USEFUL FOR

Electrical engineering students, circuit designers, and anyone studying capacitor behavior in DC circuits will benefit from this discussion.

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Homework Statement



Personal question: What is the voltage across each capacitor after the switch is closed?
(It was previously calculated that the current after the switch is closed is .5 A)

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Homework Equations



Q = CV
Q = Qo*e^(-t/RC)
V = IR

The Attempt at a Solution



The answer is 20 V for the 5uF capacitor, but I do not understand why the voltage for the 5 uF capacitor is the same as the voltage across the 40 ohm resistor.

I have no idea how to calculate the voltage for the 10 uF capacitor.
 
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Presumably you're looking for the voltage across the capacitors a "long time" after the switch is closed, after the transients have died away and everything is static?

Consider that at that time the currents through the capacitors will all be zero (we've reached steady state for a DC circuit) , so as far as the resistance network around the capacitors is concerned, the capacitors no longer exist. See if you can identify a resistive voltage divider that's setting the final voltages at key points in the circuit.
 

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