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RC circuit problem

  • Thread starter SamTsui86
  • Start date
  • #1
31
0

Homework Statement



In Figure P18.50, suppose that the switch has been closed for a length of time sufficiently long enough for the capacitor to become fully charged. (R = 12.0 k, R2 = 17.0 k, R3 = 1.00 k, V = 9.70 V)

The picture is under attachment

a) Find the steady-state current in each resistor.
I1 = µA?
I2 = µA?
I3 = µA ?

(b) Find the charge on the capacitor.
µC ?


Homework Equations



R = V / I

q = Q e^(-t/RC)

The Attempt at a Solution



Well, since after the switch is closed, I figured all 9.7 V goes to the first resistor, so I used R = V / I to get the current for the first one. But it's wrong.
 

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Answers and Replies

  • #2
berkeman
Mentor
56,814
6,783
It's wrong because there is a voltage divider formed with one of the other two resistors in the steady state. Which one? In the steady state, what is the voltage across the capacitor?
 

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