Question

A 285-Ω resistor is in series with a 35.5 μF capacitor and a 27.0-V voltage source with the circuit switch open and the capacitor uncharged.

(a) What is the time constant of this RC circuit?
10.1175 ms

(b) Calculate the maximum charge the capacitor can accumulate.
.000972 C

(c) Calculate the charge on the capacitor 5.25 ms after the switch is closed.
.0005785083113C

Please check my answers.

Thanks!

Answer 1

given
R = 285 ohm
C = 35.5 micro F
V_battery = 27.0 V

a) Time constant of the circuit, T = R*C

= 285*35.5*10^-6

= 0.0101175 s (or) 10.1175 ms <<<<<<<------------Answer

b) maximum charge on the capacitor, Q_max = C*V_battery

= 35.5*10^-6*27

= 0.0009585 C <<<<<<<------------Answer

c) at time t = 5.25 ms

Q = Q_max*(1 - e^(-t/T))

= 0.0009585*(1 - e^(-5.25/10.1175))

= 0.0003880 C <<<<<<<-------------Answer