1. What is the Power Formula?

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

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: For DC circuits or AC circuits with purely resistive loads, the power factor is 1. For AC circuits with reactive components, the power factor represents the phase difference between voltage and current.

3. Importance of Power Calculation

Details: Accurate power calculation is crucial for circuit design, energy consumption estimation, electrical system sizing, and safety considerations.

4. Using the Calculator

Tips: Enter voltage in volts, current in amperes, and power factor (between 0 and 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 in an AC circuit, representing how effectively current is being converted into useful work.

Q2: When should I use power factor = 1?
A: Use PF=1 for DC circuits or purely resistive AC loads (like incandescent lights or heaters). For motors, transformers, or fluorescent lights, use the actual PF.

Q3: What are typical power factor values?
A: Induction motors: 0.85-0.9, fluorescent lights: 0.5-0.9, computers: 0.6-0.7. Unity (1) for resistive loads.

Q4: How does power factor affect energy bills?
A: Many utilities charge commercial customers extra for low power factor (<0.95) as it indicates inefficient power usage.

Q5: Can I calculate current from power and voltage?
A: Yes, rearranged formula: I = P / (V × PF). Useful for circuit breaker sizing.