1. What is Capacitive Reactance?

Capacitive reactance (X_C) is the opposition that a capacitor offers to alternating current (AC) due to its capacitance. Unlike resistance, reactance depends on the frequency of the AC signal.

2. How Does the Calculator Work?

The calculator uses the capacitive reactance formula:

Where:

• \( X_C \) — Capacitive reactance (Ω)
• \( f \) — Frequency (Hz)
• \( C \) — Capacitance (F)
• \( \pi \) — Pi (~3.14159)

Explanation: The reactance decreases with increasing frequency and capacitance. At DC (0 Hz), the reactance is theoretically infinite (open circuit).

3. Importance of X_C Calculation

Details: Calculating capacitive reactance is essential for designing filters, timing circuits, impedance matching, and analyzing AC circuits with capacitors.

4. Using the Calculator

Tips: Enter frequency in hertz (Hz) and capacitance in farads (F). For practical values, you may need to use scientific notation (e.g., 1e-6 for 1μF).

5. Frequently Asked Questions (FAQ)

Q1: Why does reactance decrease with frequency?
A: At higher frequencies, the capacitor has less time to charge/discharge, effectively offering less opposition to current flow.

Q2: What happens at DC (0 Hz)?
A: The reactance becomes infinite, meaning a capacitor blocks DC current completely (after initial charging).

Q3: How does reactance affect phase in AC circuits?
A: Current in a capacitor leads voltage by 90° in phase, unlike resistors where they are in phase.

Q4: What are typical capacitor values used in circuits?
A: Common values range from picofarads (pF) to millifarads (mF), with microfarads (μF) being very common.

Q5: How is this different from inductive reactance?
A: Inductive reactance (X_L) increases with frequency (X_L = 2πfL) and causes current to lag voltage.