How Is Charge Calculated in a Two Loop RC Circuit After the Switch Opens?

[Gee Wiz]

Is there a complete path (a circuit) though R1 and R2 to the capacitor when the switch is open?

Okay, so for this part (figuring out R for the time constant) do i just include the resistors that are in the new circuit with the capacitor. Let me try to explain, when the switch is open i can basically ignore that wire and everything that feeds off only that wire. So, in this case the battery, R4, and R1. Is that correct logic?

 

[gneill]

Okay, so for this part (figuring out R for the time constant) do i just include the resistors that are in the new circuit with the capacitor. Let me try to explain, when the switch is open i can basically ignore that wire and everything that feeds off only that wire. So, in this case the battery, R4, and R1. Is that correct logic?

Yes. Current can only flow when there is a closed loop.

 

[Gee Wiz]

Awesome. Thank you so much. The whole talk through was very helpful, and it was better than just getting the right answer.

 

[gneill]

Awesome. Thank you so much. The whole talk through was very helpful, and it was better than just getting the right answer.

I'm very happy to have helped

 

[rude man]

Well immediately after it would just be C=Q(max)/V...?

Did we ever come up with the right Qmax across C? Last I saw was Qmax = CV but V is the battery so that equation is incorrect.

 

[gneill]

Did we ever come up with the right Qmax across C? Last I saw was Qmax = CV but V is the battery so that equation is incorrect.

When I saw that equation I assumed that here V was meant to be the voltage across the capacitor; The OP did find the initial charge on the capacitor (180.496uC), which leads one to believe that he had a handle on the voltage, too.

 

[rude man]

when i saw that equation i assumed that here v was meant to be the voltage across the capacitor; the op did find the initial charge on the capacitor (180.496uc), which leads one to believe that he had a handle on the voltage, too.

10-4.