Question

Q5) In the circuit below the switch S, has been in open position for t < 0 for a long time, but it closes at t = 0. Find the capacitor voltage (Vc) for t <0 and t > 0. C1 Vs +L S1 R2 V = 10 V 1s = 1 A R= 20 R = 40 R1 w CSF

Answer 1

Behaviour of Capacitor during different intervals of time are different.

For t<0 , Capacitor behaves as Open Circuit

For t>0 , Capacitor behaves as Short circuit

Given, СІ ht V a 10 v tro Is ТА Si SR2 f) Is V R, 22 R2 = 42 Ri ci=5F CI th Rz tro Vs Is R2 R1 ५.2 G HE At too + Na 4V According KVL, Tov 10 - Vc, -4 = 0 22 Vc, (o) = = 6 V So, for tco * Capacitor voltage Vc,(0) = 6V

for too Switch is being closed, 6V ci 10-6-vc HL VCI 4V lov for too 21 Capacitor voltage Vci =40