Question

Consider an RC circuit with E = 9.00 V, R = 165 ohms, and C = 55.7 uF.

A) Find the time constant for the circuit. (in m/s)
B) Find the maximum charge on the capacitor. (in uC)
C) Find the initial current in the circuit. (in mA)

Answer 1

(a)
Time constant for the given RC circuit is
T = RC
= (165 ohm)(55.7 x 10^-6 F)
= 9.19 x 10^-3 s
= 9.19 ms

(b)
Maximum charge in the capacitor is
Q_max = CE
= (55.7 x 10^-6 F)(9.00 V)
= 0.50 x 10^-3 C
= 0.50 mC

(c)
Initial current in the circuit is
I = E / R
= (9.00 V) / (165ohm)
= 0.0545 A