Energy stored in a capacitor

Abdul Quadeer

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?

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Antiphon

Yes. At T=inf the current through the capacitors is zero.

SammyS

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.

Abdul Quadeer

So you mean voltage drop across any capacitor is V ?

SammyS

No.

As t → ∞ :

The only current flowing is through R₁ and R₂.

What is the voltage drop across R₂?

Abdul Quadeer

Its V/3
Thank you!!

SammyS

Correct !