1. What is RC Circuit Impedance?

Impedance (Z) in an RC (resistor-capacitor) circuit is the total opposition to current flow, combining both resistance (R) and capacitive reactance (Xc). It's measured in ohms (Ω) and varies with frequency.

2. How Does the Calculator Work?

The calculator uses the RC impedance formula:

Where:

• \( Z \) — Impedance (ohms)
• \( R \) — Resistance (ohms)
• \( f \) — Frequency (Hz)
• \( C \) — Capacitance (Farads)
• \( \pi \) — Approximately 3.14159

Explanation: The equation combines the resistive and reactive components of the circuit using the Pythagorean theorem since they are 90° out of phase.

3. Importance of Impedance Calculation

Details: Calculating impedance is essential for designing filters, analyzing AC circuits, determining voltage drops, and ensuring proper signal transmission in electronic circuits.

4. Using the Calculator

Tips: Enter resistance in ohms, frequency in hertz (Hz), and capacitance in farads (F). All values must be positive numbers. For microfarads (μF), multiply by 10^-6.

5. Frequently Asked Questions (FAQ)

Q1: What happens to impedance as frequency increases?
A: Impedance decreases with increasing frequency because capacitive reactance (Xc = 1/(2πfC)) becomes smaller.

Q2: What is the phase angle in an RC circuit?
A: The phase angle θ = arctan(-Xc/R), representing how much current leads voltage in the circuit.

Q3: What's the difference between impedance and resistance?
A: Resistance opposes DC current, while impedance opposes AC current and includes both resistive and reactive components.

Q4: How does capacitance affect impedance?
A: Larger capacitance reduces impedance (at a given frequency) because it increases current flow through the capacitor.

Q5: What is the impedance at DC (0 Hz)?
A: At DC, the capacitor acts as an open circuit, so impedance is effectively infinite (only the resistor matters).