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, between 0 and 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 ratio of real power to apparent power.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for circuit design, energy consumption estimation, electrical system sizing, and determining the efficiency of electrical devices.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, 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 (watts) to apparent power (volt-amperes). It represents how effectively current is converted to useful work.

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

Q3: What's the difference between real, apparent, and reactive power?
A: Real power (watts) does actual work, apparent power (VA) is voltage × current, and reactive power (VAR) is power that oscillates between source and load.

Q4: How can I improve power factor?
A: Using power factor correction capacitors, selecting properly sized motors, or using active power factor correction circuits.

Q5: Does this formula work for three-phase power?
A: For balanced three-phase systems, multiply by √3 (P = √3 × V × I × PF). For unbalanced systems, calculate each phase separately.