RC circuit

Definition

An RC circuit consists of a resistor (R) and a capacitor (C) connected in series or parallel. It is fundamental in analyzing transient responses in circuits.

5 Must Know Facts For Your Next Test

1. The time constant, $\tau$, of an RC circuit is given by $\tau = RC$.
2. In a charging RC circuit, the voltage across the capacitor asymptotically approaches the supply voltage following $V(t) = V_{max}(1 - e^{-t/RC})$.
3. In a discharging RC circuit, the voltage across the capacitor decreases exponentially following $V(t) = V_0 e^{-t/RC}$.
4. The steady-state current in an RC circuit with DC supply eventually becomes zero as the capacitor fully charges.
5. Kirchhoff's Voltage Law (KVL) applies to RC circuits, ensuring the sum of voltages around any closed loop equals zero.

Review Questions

• What is the formula for the time constant in an RC circuit?
• How does the voltage across a capacitor change over time when charging in an RC circuit?
• What happens to the current in an RC circuit once the capacitor is fully charged?

Related terms

Resistor: A passive electrical component that resists current flow, causing a drop in voltage.

Capacitor: A passive electrical component that stores energy in an electric field, characterized by its capacitance.

Kirchhoff's Voltage Law: $\text{KVL states that the sum of all electrical potential differences around any closed loop or mesh is equal to zero.}$