3. Voltage in RC Circuit For the circuit shown determine the expression for the voltage across...

Solhi- niven circuit I kn + 1.ska lov 333 xf ta Vt=0 now switch was closed before find initial voltage t=0, so let capacitor, which across us balgaves as open circuit for stedy state in dc. iie Iku + 1+ lska Vc (0) { بیاد W from voltage division rule 10 X 1.5 km Vcco-) - 6V (1 km. int 1.5kn) we that know now voltage across Capacitor is continuous i.e. it can not change instantaneouse y. hence Veco-) Vc (ot) = 6V will how look like after switch is circuit opened,

+ + 1.5kn Vu 333MF Vc V(ot) = 60 how above circuit is standard RC circuit and for standard RC circuit voltage across capacitor (same as vu) is given the V (00) + (vecot) – Velos) e (t) = C where Vc() = voltage across capacitor when too Vecos) will be zero, o, because in there our case is no source in the circuit hence Vcco) = vetot) initial roltage on capacitor Vecot) = in our case z = time constant of the circuit 7 = RC in our case T= (isxio3) * (333x1000) z = 0.4995 seconds Hence Vc(t) = u(t)= 0 + (0-0)2-44999 - 2.002t or Vy(t) = 6 e Volts

Hence -2-002t 6 e Valt) volts tzo Ans value of Un at t = 25 ms now - 2.002X25X10-3 6.e ur = Vu 5, 7071 Volts hence value of Un at t-asms is 5.7071 volts