You need to define what direction i1 is in. Don't make people (e.g., a grader) guess or reverse engineer your work.Hi,
Thanks for reply..
when switch is opened for long time, the voltage across capacitor is 15v
when the switch is closed at t = 0 , it become an initial voltage so v0 = 15v
in order to find v_inf across capacitor after the switching takes place.. the open circuit voltage across capacitor by applying kvl across loop
7.5+6i1+2i1+15 = 0
which gives
i1 = 2.81
Huh? This equals 18.54 (no units since you don't believe in units).so the voltage across Open circuit
15-2*i1 + -(7.7-6*i1) = 9.376
You really, really, really need to track your units properly. Most mistakes you make (but not the ones you made here) will screw up the units and let you catch them almost immediately -- but only if the units are there to be messed up.the eq for Rc transient response is
v_inf + (v_0 - v_int) exp(-t/tau)
9.376 + (15 - 9.376) exp(-t/tau)
9.376 + (5.624)exp(-t/tau)
the value of time constant tau = R * C
r = 2||6 = 1.5
tau = 1.5 * 1/3 = 0.5 sec.
It did take some time to get ie.. But i think i solved it..
Thanks for reply.
by Aaron Carman
by Jake Hertz
by Jake Hertz
by Duane Benson