Capacitors - please, need help

  • Thread starter Thread starter joker_900
  • Start date Start date
  • Tags Tags
    Capacitors
joker_900
Messages
53
Reaction score
0
Capacitors - please, need urgent help!

Homework Statement


I've attached the circuit diagram but it's basically a cell connected in series with a 10kohm resistor, and then a 20microfarad capacitor and 22kohm resistor connected in parallel.

The capacitor begins charging at t=0. Show that the voltage across the capacitor as a function of time is Vc(t)=4.125(1 - exp(-t/0.1375))


Homework Equations





The Attempt at a Solution


Well i know that in a simple one resistor one capacitor series circuit, the current through the resistor is I=I0e^(-t/RC), and the voltage across the resistor is V=V0e^(-t/RC) (where V0=EMF)


Now i thought this same relationship might apply to the 10kohm (R1) resistor, as initially it's voltage = EMF, and as the capacitor charges, Vc increases and the voltage across R1 therefore decreases. However, in this situation, there is always current flow and so the voltage across R1 does not become zero.

I thought about applying kirchhoffs current law, but this did not seem to get me anywhere.


I am thoroughly confused, PLEASE HELP!

Thanks
 

Attachments

  • Untitled.jpg
    Untitled.jpg
    6.3 KB · Views: 439
Physics news on Phys.org

Similar threads

Replies
2
Views
1K
Replies
20
Views
3K
Replies
9
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 62 ·
3
Replies
62
Views
6K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K