problem solving
posted by bobby on .
if a circuit has a3.9k resistor and a5uf capacitor, find the current flow in the circuit at 0.005 seconds, if the maximum current flow in the circuit is 105mA

T = RC = 3.9K * 5uF = 19.5 Milliseconds
= Time Constant.
t/T = 5ms / 19.5ms = 0.256.
i = 105*e^(t/T),
i = 105*e^(0.256) = 81.3mA.
NOTE: If R was in ohms and C in Farads,
the Time Constant would be in seconds.