R = 3.9k = 3900 Ohms.
C = 5 Farads.
t = 0.005 Seconds.
RC = 3900 * 5 = 19500 Seconds.
t/RC = 0.005 / 19500 = 2.564*10^-7s.
i = I / e^(t/RC),
i = 1.5 / e^(2.564*10^-7),
i = 1.5/1.000000256 = 1.4999996mA.
If C = 5uF:
RC = 3.9k * 5uF = 19.5 mS = 0.0195s.
t/RC = 0.005/0.0195 = 0.2564s.
i = I / e^(t/RC),
i = 1.5 / e^(0.2564),
i = 1.5 / 1.292 = 1.16 mA.
If a circuit has a 3.9k resistor and a 5F capacitor, find the current flow in the circuit at 0.005 seconds, if the maximum current flow in the circuit is 1.5mA.
1 answer
1 answer