Suppose that the current through a conductor decreases exponentially with time according to the equation I (t) = Ioe-t/r where I0 is the initial current (at t = 0), and + is a constant having dimensions of time. Consider a fixed observation point within the conductor.
(a) How much charge passes this point between t = 0 and t = r?
(b) How much charge passes this point between t = 0 and t = 10r?
(c) What If? How much charge passes this point between t = 0 and t = 0?