How many time constants will elapse before the cha

Question

How many time constants will elapse before the charge on a capacitor falls to 0.1% of its maximum value in a discharging RC circuit?

Aditi Chauhan · Accepted Answer

Sol. q = Qe^–t/RC q = 0.1 % Q RC ⇒ Time constant = 1 * 10^–3 Q So, 1 * 10^–3 Q = Q * e^–t/RC ⇒ e^–t/RC = ln 10^–3 ⇒ t/RC = –(–6.9) = 6.9

How many time constants will elapse before the charge on a capacitor falls to 0.1% of its maximum value in a discharging RC circuit?