1. The problem statement, all variables and given/known data http://imgur.com/VsDrQ,dJ2iv 2. Relevant equations Current in loop 1: i_1 going counter-clockwise Current in loop 2: i(t) going counter-clockwise Before opening switch: we know that 2 loops exist, left and right. also the current is constant because it says the circuit was at rest for a long time. After we open the switch, we know that the left loop is shorted out, and we somehow use (a) and (b) and plug it into our equations and solve? We also know that i(0-) = i(0+) 3. The attempt at a solution Before opening the switch: Loop 1 (left) : -v_initial - (i_1 - i(t)) R = 0 ---> v_initial = -R i_1 + R i(t) Loop 2 (right): i(t) = - R i(t) + r i_1 - 1/c integral i(t)dt After switch is open: i(0+) = 1 v(2microseconds) = 1/e ... I don't understand how to proceed from here? What exactly do I have to do.. I'm stuck. Please let me know as soon as possible. Thanks.