Another circuit of interest is a resistor and a capacitor co

Another circuit of interest is a resistor and a capacitor connected in series in a closed loop as shown in the figure below. This makes for a time-delay circuit.

Solution

a)

Time constant, T = R*C

= 20*10*10^-6

= 2*10^-4 s

b)

Q = Qo*e^(-t/RC)

So, for Q = 0.5uC

So, 0.5 = 1*e^(-t/2*10^-4)

So, t = 1.39*10^-4 s <-------answer

c)

current in the resitance is given by :

I = -dQ/dt = (Qo/RC)*e^(-t/RC)

d)

By work energy principle,

total energy dissipated = initital energy stored

= Qo^2/2C

= (1*10^-6)^2/(2*10*10^-6)

= 5*10^-8 J

e)

It will be equal to the Q^2/2C