At t = 0, C1, C2, C3 acts as short. ∴ entire voltage will appear cross R. At t increases the voltage across the resistance decrease exponentially. T = RCnet = 10 x 2.5 x 10-6 = 25 μ sec Initial voltage VR = V0e-t/RC at t = 0 = 100 = 100 e-t/25x10-6 V. VR = 100 e-40x104t V. At t = ∞, VR = 0 The charge C0 will be distributed in C1, C2, C3 and no current will flow.