1. What is Real Power in AC Circuits?

Real power (P) represents the actual power consumed by electrical devices in an AC circuit that performs useful work. Unlike apparent power, real power accounts for the phase difference between voltage and current through the power factor.

2. How Does the Calculator Work?

The calculator uses the real power formula:

Where:

• \( P \) — Real power (watts, W)
• \( V \) — RMS voltage (volts, V)
• \( I \) — RMS current (amperes, A)
• \( \cos(\phi) \) — Power factor (unitless)

Explanation: The formula calculates the actual power consumed by accounting for the phase relationship between voltage and current in AC circuits.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for electrical system design, energy consumption analysis, circuit protection sizing, and power quality assessment in AC systems.

4. Using the Calculator

Tips: Enter RMS voltage in volts, RMS current in amperes, and power factor (between 0 and 1). All values must be valid (voltage > 0, current > 0, power factor 0-1).

5. Frequently Asked Questions (FAQ)

Q1: What is RMS voltage and current?
A: RMS (Root Mean Square) values represent the equivalent DC values that would produce the same power dissipation in a resistive load.

Q2: What is power factor?
A: Power factor is the ratio of real power to apparent power, representing the phase difference between voltage and current waveforms.

Q3: What are typical power factor values?
A: Power factor ranges from 0 to 1. Resistive loads have PF=1, inductive loads (motors) typically 0.7-0.9, and capacitive loads can lead or lag.

Q4: Why is power factor important?
A: Low power factor increases current for the same real power, leading to higher energy losses, larger conductors, and potential utility penalties.

Q5: How is this different from DC power calculation?
A: DC power is simply P = V × I. AC power requires the power factor multiplier to account for phase differences between voltage and current.