1. What is Wattage?

Wattage (power) is the rate at which electrical energy is transferred by an electric circuit. It's measured in watts (W) and represents the actual power consumed by a device.

2. How Does the Calculator Work?

The calculator uses the wattage 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, power factor is 1. For AC circuits with reactive components, power factor accounts for phase difference between voltage and current.

3. Importance of Power Factor

Details: Power factor indicates how effectively electrical power is being used. A lower power factor means higher current is required for the same real power, leading to increased energy losses in distribution systems.

4. Using the Calculator

Tips:

• For DC circuits, use power factor = 1
• For AC resistive loads (heaters, incandescent lights), use power factor ≈ 1
• For inductive loads (motors, transformers), power factor is typically 0.7-0.9
• For capacitive loads, power factor can be leading (positive phase angle)

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between real power and apparent power?
A: Real power (watts) is the actual power consumed, while apparent power (VA) is the product of voltage and current. The ratio is the power factor.

Q2: When should I use power factor < 1?
A: For AC circuits with inductive or capacitive loads where current and voltage waveforms are not perfectly in phase.

Q3: How can I improve power factor?
A: For inductive loads, adding capacitors can correct power factor. For capacitive loads, inductors may be needed.

Q4: What's a typical power factor for household appliances?
A: Resistive appliances ≈1, fluorescent lights 0.9-0.95, induction motors 0.7-0.9, small electronics 0.6-0.8.

Q5: Why does power factor matter?
A: Utilities often charge commercial customers for low power factor because it increases current and system losses without delivering more useful power.