1. What is the Power Equation?

The power equation (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 and DC circuits.

2. How Does the Calculator Work?

The calculator uses the power equation:

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, power factor is 1. For AC circuits, 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 electrical components.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between real power and apparent power?
A: Real power (P) is the actual power consumed, while apparent power (S = V×I) includes reactive power. Power factor is the ratio of real to apparent power.

Q2: When should I use power factor less than 1?
A: For AC circuits with inductive or capacitive loads (motors, transformers, etc.). Pure resistive loads have PF = 1.

Q3: How does power factor affect energy consumption?
A: Lower power factor means more current is needed for the same real power, increasing energy losses in distribution systems.

Q4: Can this calculator be used for three-phase systems?
A: For three-phase, you need to multiply by √3 (line-to-line voltage) or 3 (line-to-neutral voltage) depending on configuration.

Q5: Why is power measured in watts?
A: Watts represent the rate of energy conversion (1 watt = 1 joule per second). It's the standard unit for real power.