1. What is the Power Wattage Formula?

The Power Wattage Formula (P = V × I × PF) calculates the real power in an electrical circuit by multiplying voltage (V), current (I), and power factor (PF). It's fundamental in electrical engineering and power system 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, between 0 and 1)

Explanation: For purely resistive loads (PF=1), power equals voltage times current. For reactive loads, the 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 and systems.

4. Using the Calculator

Tips: Enter voltage in volts, current in amperes, and power factor (1 for DC or purely resistive AC circuits). 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, representing how effectively current is converted to useful work (1 = perfect, 0 = no real power).

Q2: When should I use PF = 1?
A: For DC circuits or purely resistive AC loads (like incandescent lights or heaters). For inductive loads (motors, transformers), PF is typically 0.8-0.95.

Q3: How does this differ from apparent power?
A: Apparent power (VA) is V × I without PF. Real power (W) accounts for the actual work performed.

Q4: What's typical household voltage?
A: 120V in North America, 230V in most other countries. Large appliances may use 240V (US) or 400V (EU three-phase).

Q5: Why calculate power in watts?
A: Watts measure actual energy consumption. Utility bills are based on watt-hours (Wh), calculated from real power over time.