# Energy stored in a capacitor

by zorro
Tags: capacitor, energy, stored
 P: 1,394 1. The problem statement, all variables and given/known data Long time after closing K1,k2 and k3 the energy stored in each capacitor is? 3. The attempt at a solution My method is to find out an expression for the current through the capacitor (of net capacitance 2C) at any time t and use I = CdV/dt to find out V across it at t=inf. However this method appears to be very long. Is there any shortcut? Attached Thumbnails
 P: 1,781 Yes. At T=inf the current through the capacitors is zero.
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P: 7,808
 Quote by Antiphon Yes. At T=inf the current through the capacitors is zero.
Also notice: that will leave you with a fairly simple circuit. The capacitors in combination with R3 are in parallel with R[SUB]2[/SUB, but the voltage drop across R3 is zero since there is no current through it.

 P: 1,394 Energy stored in a capacitor So you mean voltage drop across any capacitor is V ?
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P: 7,808
 Quote by Abdul Quadeer So you mean voltage drop across any capacitor is V ?
No.

As t → ∞ :

The only current flowing is through R1 and R2.

What is the voltage drop across R2?
 P: 1,394 Its V/3 Thank you!!
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