1. What is the Power Formula?

The power formula (P = V × I × PF) calculates electrical power in watts (W) from voltage (V), current (I), and power factor (PF). 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 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 resistive AC loads, power factor is 1. For reactive loads, power factor represents the 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 components like wires and fuses.

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 is power factor?
A: Power factor is the ratio of real power to apparent power, representing the efficiency of power usage in AC circuits.

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

Q3: How does this differ for three-phase power?
A: Three-phase power uses \( P = \sqrt{3} \times V \times I \times PF \) for line-to-line voltage.

Q4: What's the difference between watts and volt-amperes?
A: Watts measure real power, while volt-amperes measure apparent power (V × I). They're equal when PF = 1.

Q5: Why is power calculation important?
A: It helps determine energy usage, circuit loading, and ensures electrical systems operate safely and efficiently.