Capacitor charging a capacitor

[physicsboy1]

Hi there!

I have a problem that I would like explaining if possible (I like to go a bit beyond the GCSE course to get a deeper understanding of the topics!).

Basically if I had a charged capacitor Cx with a voltage Vo across it which is connected in series with another capacitor Cy and a resistor. The switch is closed so that Cx now discharges across Cy (causing Cy to charge up) and the resistor.

My question is what would the voltage graphs look like for both of the resistors, would they both end up with the same voltage across them (I know the shapes would be the the typical capacitor discharging for Cx and capacitor charging for Cy) or would they both have different voltages? I also think they would both store exactly the same charge once the system has come to equilibrium.

Anyone help me out?

btw here is the info I was looking at: http://web.mit.edu/viz/EM/visualizations/coursenotes/modules/guide05.pdf

 

[phinds]

Once the charge is finished distributing, you have 2 caps in parallel with the resistor not counting, since no current is flowing at that time.

Can two caps in parallel have different voltages?

 

[physicsboy1]

Once the charge is finished distributing, you have 2 caps in parallel with the resistor not counting, since no current is flowing at that time.

Can two caps in parallel have different voltages?

If everything is originally in series how does it become parallel when the charge has been distributed sorry?

 

[phinds]

If everything is originally in series how does it become parallel when the charge has been distributed sorry?

Draw two caps in a loop. You can say they are in series OR parallel, but the voltage will act like they are in parallel.

 

[HalfLostAndSearching]

Hello! Thank you for providing the information about your question. It sounds like you are describing a series RC circuit, where a capacitor Cx is connected in series with another capacitor Cy and a resistor. When the switch is closed, Cx will discharge across Cy and the resistor, causing Cy to charge up.

To answer your question, the voltage graphs for both resistors would not be the same. The voltage across the resistor connected to Cx would decrease exponentially as Cx discharges, while the voltage across the resistor connected to Cy would increase exponentially as Cy charges up. However, the voltages would eventually reach the same equilibrium value once the system has reached steady state.

This is because in a series RC circuit, the total voltage across the capacitors must equal the voltage across the resistor. So as Cx discharges, the voltage across the resistor connected to it decreases, but the voltage across Cy increases to compensate for this. In the end, the total voltage across both capacitors and the resistor will be the same.

As for the charge stored in both capacitors, they would indeed be the same once the system reaches equilibrium. This is because charge is conserved in a circuit, so the charge that initially was stored in Cx would transfer to Cy as it charges up.

I hope this helps clarify your question! If you have any further questions, please don't hesitate to ask. Keep up the curiosity and good luck with your studies!