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 varies with frequency and is measured in ohms (Ω).

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)
• \( \pi \) — Approximately 3.14159

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

3. Importance of Capacitive Reactance

Details: Understanding capacitive reactance is essential for designing and analyzing AC circuits, filters, timing circuits, and power factor correction systems.

4. Using the Calculator

Tips: Enter frequency in hertz (Hz) and capacitance in farads (F). For practical capacitors, you may need to use values like microfarads (μF) or picofarads (pF).

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 presenting 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?
A: In a purely capacitive circuit, current leads voltage by 90 degrees.

Q4: What's the difference between reactance and impedance?
A: Reactance is the imaginary part of impedance. Impedance combines resistance and reactance (Z = R + jX).

Q5: Can reactance be negative?
A: Capacitive reactance is always positive in this formula. The negative sign in impedance calculations indicates the phase relationship.