- #1
ChillFreeze
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Homework Statement
The problem is:
After being closed for along time, the switch shown in figure 1 opens at t=0. Find IA for all time.
Homework Equations
I believe it would be i(t)=Ioe^(-t/(CReq)) or i(t)=(Q/P)+Ae^(-Pt)
Q/p=Vo/r and 1/p is time constant or t/(CReq)
The Attempt at a Solution
I find that if i label the inductor as Vc i find the voltage as 0 at time 0 because the capacitor becomes a short over a long period of time. I get what is in t<0 and when t>0 . I believe i need to find Req but the problem is how do i find that with the wire between the two resistors? Or is it just the 1k ohms anyway? After finding Req i know that I=if+in and in=Ke^(t/(CReq). t>0 and if=10/2000=1/200 so i=(1/200)+Ke^(t/(CReq) t>0 now i think i need to find out the current so that i can have whatever current i get say B so B=1/200 + K the K = B-1/200
so that it means i=(1/200)+(K)e^(t/CReq) Then using B (current) for all t i=B+B(1-e^(-t/CReq)u(t)
So how do i find what i called B and how do i find the original Req?
Thanks to whoever can help me. Also i placed the original diagram, the t>0 and t<0 diagrams as well. Thanks again