RC circuit determines the capacitor's charging rate.
In RC (resistive and capacitive) circuits, a capacitor's time constant is the number of seconds required to charge it to 63.2% of the input voltage.
This duration is described by a single time constant. After two time constants, the capacitor will be charged to 86.5% of the input voltage.
The RC time constant, also referred to as tau, is the time constant (in seconds) of an RC circuit and is obtained by multiplying the circuit resistance (in ohms) by the circuit capacitance (in farads), This transient reaction time T is stated in terms of = R x C, where R is the resistor value in ohms and C is the capacitor value in farads.
