A 20.0 \mu F capacitor initially charged to 20.0 \mu C is discharged through a 1.90 k\Omega resistor. How long does it take to reduce the capacitor's charge to 5.00 \mu C?

1 answer

1. The charge of the discharging capacitor, as a function of t, is:
   
   Q(t) = Qo* e^(-t/RC)
   
   Qo is the initial charge, RC is the time constant, which in this case is 1900*20*10^-6 = 0.038 seconds
   
   So, solve
   
   5*10^-6 = 20*10^-6*e^(-t/0.038)
   
   ln(1/4) = -t/0.038
   
   t = ?

   Answer ID
   523820

   Created
   April 1, 2011 5:44am UTC

   Rating
   0

   URL
   https://questions.llc/answers/523820