Question

Question 2: (20 pts.) In the circuit below E =12V, R1 = R2 = 10 ohm, and C = 4 uF. Initially the switch Sis open. At t=0 the switch S is closed. (a) What is the current i, through R, at t= 0 and t = 00 ? (b) Draw a qualitative graph of the potential drop V, through R. from t=0 to t=00. (c) When C is fully charged, switch S is opened. What is the current iz trough the resistor R2 at t= 0 and t = 00 ? (d) What is the time constant of this circuit when S is open during the discharge of C ? S E R2 R m

Answer 1

too, Capacitor open circuited. (a) At t-o, Switch is closed and capacitar is shoes! circunted as i nitally its it is dis charged TR1 + RZOR 12V lor RE Trolt=0) 12v 1-2 A lon iRi (1=o-- L-ZA At 124 6) TRI (1-2)=0 A. URI ve to voltage arooss capacita incredjes as t-o, and resista voltage VR1 = (1-2x ) e doops exponentially as t-yoo and -tly reachs zero attoo, le tly NET +12V voltage across RI

(e) when switchs is open when capacitor is fully charged =<"12 10.12 charged to e slon iR2(t-o)= 12V to -142 A voltage across copeala cannot change instantaneously] Capautor discharges to ou and no current At to do in circuito I (0) =0 A d) For when switch is open circited Hi 3er &RI I= Reqc =(Ritka) Time be constante = ( 1010bdullF) (20)(4bUf =gbo els I=80us