- #1
smithisize
- 13
- 0
Homework Statement
I'm really looking for help with A.) because I think that if I could figure out A.) the rest should be ok. So, here are all parts of the question, but I'm really only concerned with A at the moment!
The diagram below depicts an RC-circuit where C = 5.40 F, R0 = 14.5Ω , R1 = 24.5 Ω, R2 = 27.5 Ω, and V = 7.50 Volts. The capacitor is initially uncharged.
This is how I drew my currents etc:
The circles are for Kirchoff Loops I tried to construct, and they're going clockwise. Along with a loop around the outside of the circuit.
A.) What is the current through R1 immediately after the switch S is closed?
B.) What is the current through R2 immediately after the switch S is closed?
C.) What is the current through the capacitor immediately after the switch S is closed?
D.) What is the current through R1 after the switch S has been closed for a very long time? Assume that the battery does not go dead.
E.)
What is the current through R2 after the switch S has been closed for a very long time? Assume that the battery does not go dead.
Homework Equations
V=IR
C=(Q/V)
The Attempt at a Solution
According to Kirchoff's Laws: I1= I2 + I3
So, since V=IR and R1 and R2 are || : I1 = (Vparallel/R1)+(Vparallel/R2) --> I1= V*(1/R1 + 1/R2)
Therefore: I1/(1/R2 + 1/R1) = Vparallel. Where I1 = V/R0.
Then, I2 = Vparallel/R1
But, that's not correct unfortunately. Where am I going wrong? Thanks!
Side note, here are the eqns I got from kirchhoffs laws (pretty sure I messed something up):
V - I1R0 - I2R1 = 0 Left loop
-I4R4 + I2R1 = 0 Right loop at t=0 (or basically zero) Also, I4=I3.
V-I1R0-I4R2 = 0 Entire loop again at t=0.