RC Circuit Discharge Conceptual Question

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SUMMARY

The discussion centers on the behavior of an RC circuit during the discharge phase when a switch is closed. Initially, the voltage at node A is 3V, while nodes B and C are at 0V, with a current of 0.25 mA. Upon closing the switch, the two 6kΩ resistors become irrelevant, leading to confusion about the flow of current from the capacitor between nodes B and C. The conclusion drawn is that the voltage across the capacitor remains constant at 3V, contradicting the solution manual's assertion that current would flow from B to C.

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DaleSwanson
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I have the solution manual, so this is more just a question of why, rather than what.

I understand that with the switch open:
vA = 3v
vB = vC = 0v
i0 = 0.25 mA

When the switch closes it creates a short that makes the two 6kΩ resistors irrelevant. What I don't understand is why anything should change then. The solution manual tells me that a current would flow from the capacitor from B to C, but why? It seems like nodes B and C should be at 0v both before and after the switch is closed.
 
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Yes, node B is at zero both before and after the switch is closed, but after the switch is closed, what is the voltage across the capacitor? Is it any different than before the switch is closed?
 
You are right--book is wrong.
 
As far as I can tell the voltage across the capacitor should always be 3v.
 

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