What is the time constant of an RC circuit?

τ = R * C

where:

τ = Time constant (in seconds)

R = Resistance of the resistor in the circuit (in ohms)

C = Capacitance of the capacitor in the circuit (in farads)

The time constant is a crucial parameter in understanding the transient behavior of RC circuits, helping to describe how quickly the capacitor charges or discharges when a voltage is applied or removed, respectively. After one time constant has elapsed, the voltage across the capacitor will have reached approximately 63.2% of its final value. After two time constants, it will be around 86.5% of the final value, and so on. The capacitor's voltage asymptotically approaches the source voltage over time, but it never reaches it completely in an ideal RC circuit.

For an RC circuit, the time constant (τ) is calculated by multiplying the resistance (R) in ohms by the capacitance (C) in farads:

τ = R * C

Where:

τ = Time constant (in seconds)

R = Resistance (in ohms)

C = Capacitance (in farads)

It's important to note that the time constant is a characteristic property of the RC circuit and can be used to determine how quickly the circuit responds to changes in voltage or current. As the time constant increases, the circuit's response becomes slower, and as it decreases, the response becomes faster.