1. What is the Power Formula?

The power formula (P = V × I × PF) calculates real power in watts from voltage, current, and power factor. It's fundamental in electrical engineering for determining the actual power consumed by AC circuits.

2. How Does the Calculator Work?

The calculator uses the power formula:

Where:

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

Explanation: For DC circuits or purely resistive AC loads, power factor is 1. For reactive loads, power factor accounts for phase difference between voltage and current.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for circuit design, energy consumption estimation, electrical safety, and proper sizing of components and wiring.

4. Using the Calculator

Tips: Enter voltage in volts, current in amperes, and power factor (0 to 1). For DC circuits or purely resistive AC loads, use power factor = 1.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between real, apparent, and reactive power?
A: Real power (P, watts) does actual work. Apparent power (S, VA) is V×I. Reactive power (Q, VAR) is stored and returned to the source.

Q2: When is power factor not 1?
A: In circuits with inductive (motors, transformers) or capacitive loads where current and voltage waveforms are out of phase.

Q3: What are typical power factor values?
A: Residential: 0.95-1.0, Industrial: 0.8-0.9, Highly inductive loads: 0.5-0.7.

Q4: How do I improve power factor?
A: Add capacitors (for inductive loads) or inductors (for capacitive loads) to bring phase angle closer to zero.

Q5: Why does power factor matter?
A: Utilities often charge more for low power factor since it increases current for the same real power, causing more line losses.