Electronics - Time Response of Reactive Circuits - Discussion

The charge on the plates of the capacitor is given as Q = CV.

This charging (storage) and discharging (release) of a capacitor's energy is never instant but takes a certain amount of time to occur with the time taken for the capacitor to charge or discharge to within a certain percentage of its maximum supply value being known as its Time Constant ( τ ).

If a resistor is connected in series with the capacitor forming an RC circuit, the capacitor will charge up gradually through the resistor until the voltage across the capacitor reaches that of the supply voltage. The time also called the transient response.

Transit comes before steady state is achieved i.e. before system becomes stable.