Circuit with an uncharged capacitor - desperate

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SUMMARY

The discussion focuses on the behavior of an uncharged capacitor in a circuit when a switch is closed. Immediately after closing the switch, the capacitor begins to charge, and the current flows through the capacitor rather than through Resistor 2, which remains inactive. This occurs because the capacitor initially acts as a short circuit, allowing current to flow into it until it reaches a certain voltage. The key equation governing this behavior is i = C (dv/dt), which describes the relationship between current, capacitance, and the rate of voltage change across the capacitor.

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  • Knowledge of current flow in electrical circuits.
  • Basic principles of electromotive force (emf) in circuits.
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circuit with an uncharged capacitor -- desperate

Homework Statement


http://img91.imageshack.us/img91/7533/physicsimage.gif
Switch S has been open for a long time. It is closed suddenly at t=0.
A long time later, it is opened.
Determine the potential across and the current through each component at the following times.

Immediately after S closes. <-- one i don't understand...
A long time after S closes.
Immediately after S is reopened.

Homework Equations


Q=CV

The Attempt at a Solution


So immediately after S closes, the capacitor charge is neutral, right? (Since it is uncharged.) The solution says that the current will not go through Resister 2.
So I do not understand why the current will not go through Resistor 2 and go through Capacitor instead.
I thought current charges cannot jump to the other side of the capacitor...There is potential difference between battery, so I thought the current will try to go through resister 2 due to the emf of the battery...
But that is not the case.

I am wondering why all currents going to R2 and C is used to charge the capacitor...
and i also do not understand why that results in no current through R2...

Thank you SO much in advance.

I am sso stuck and very desperate...

If you cannot answer all my questions, my biggest most important question is... Why does current NOT go through R2?

Again, thanks so much for your time.
 
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For the time being forget R2.
Close the switch .What happens?
 


You need another equation for the capacitor.

i = C \frac{dv}{dt}
 


rl.bhat said:
For the time being forget R2.
Close the switch .What happens?

If there is no R2, then the battery charges the capacitor.
Btw, that raises another question.
Since electrons are the charge carriers and electrons cannot ever travel to positive side of the capacitor, does the resistor 1 connected to the positive plate of the capacitor play a role? I am so confused. Thanks for your help.@Phrak:
Thank you so much for your response. I am wondering if you could elaborate a little more. ^^
 

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