1. What is the Power Formula?

The power formula (P = V × I × PF) calculates real power in watts in an AC circuit, accounting for voltage, current, and power factor. It's essential for determining actual power consumption in electrical systems.

2. How Does the Calculator Work?

The calculator uses the power formula:

Where:

• \( P \) — Power in watts (W)
• \( V \) — Voltage in volts (V)
• \( I \) — Current in amperes (A)
• \( PF \) — Power factor (unitless, 0 to 1)

Explanation: The formula calculates real power by accounting for the phase difference between voltage and current in AC circuits through the power factor.

3. Importance of Power Calculation

Details: Accurate power calculation is crucial for electrical system design, energy consumption analysis, circuit protection sizing, and efficiency calculations.

4. Using the Calculator

Tips: Enter voltage in volts, current in amperes, and power factor (0 to 1). For DC circuits, use power factor of 1. All values must be valid (voltage > 0, current > 0, 0 ≤ PF ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: What is power factor?
A: Power factor is the ratio of real power to apparent power, representing the phase difference between voltage and current in AC circuits.

Q2: What's the difference between real, apparent, and reactive power?
A: Real power (P) is actual consumed power, apparent power (S) is V×I, and reactive power (Q) is energy stored and returned in reactive components.

Q3: When should I use power factor less than 1?
A: For AC circuits with inductive or capacitive loads (motors, transformers, etc.). For DC circuits or purely resistive AC loads, use PF=1.

Q4: How does power factor affect energy consumption?
A: Lower power factor means more current is needed to deliver the same real power, increasing losses in distribution systems.

Q5: What are typical power factor values?
A: Residential: 0.95-1, Industrial: 0.8-0.9, Motors at full load: 0.85, Transformers: 0.8-0.95.