1. What is the Power Formula?

The power formula (P = V × I × PF) calculates electrical power in watts from voltage (V), current (I), and power factor (PF). It's fundamental in electrical engineering and power systems analysis.

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 shows that power is the product of voltage and current, adjusted by the power factor which accounts for phase difference in AC circuits.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for circuit design, electrical system sizing, energy consumption estimation, and equipment selection.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, and power factor (1 for DC circuits or resistive AC loads). 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 AC circuits, ranging from 0 to 1. It accounts for phase difference between voltage and current.

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

Q3: What are typical power factor values?
A: Motors: 0.8-0.9, Fluorescent lights: 0.7-0.9, Computers: 0.6-0.7, Resistive loads: 1.0.

Q4: How does this relate to energy consumption?
A: Energy (kWh) = Power (kW) × Time (hours). Accurate power calculation is needed to estimate energy use.

Q5: What about three-phase power?
A: For balanced three-phase systems, multiply by √3 (≈1.732): P = √3 × V × I × PF.