1. What is the Power Equation?

The power equation (P = V × I × PF) calculates the real power in an electrical circuit, accounting for voltage, current, and power factor. It's fundamental in electrical engineering and power system analysis.

2. How Does the Calculator Work?

The calculator uses the power equation:

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 purely resistive loads (like heaters), PF=1. For inductive loads (like motors), PF is typically 0.8-0.9.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for circuit design, energy consumption estimation, electrical safety, and proper sizing of components and wiring.

4. Using the Calculator

Tips: Enter voltage in volts, current in amperes, and power factor (default is 1 for DC or resistive AC circuits). All values must be valid (V > 0, I > 0, 0 ≤ PF ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: What if I don't know the power factor?
A: For DC circuits or purely resistive AC loads, use PF=1. For typical household appliances, 0.8-0.95 is common.

Q2: How does this differ from apparent power?
A: Apparent power (VA) is V×I without PF. Real power (W) accounts for the phase difference between V and I.

Q3: Can I use this for three-phase systems?
A: For balanced three-phase, multiply by √3 (P = √3 × V × I × PF).

Q4: Why is power factor important?
A: Low PF increases current for the same real power, requiring larger conductors and causing more line losses.

Q5: How accurate is this calculation?
A: It's theoretically exact, but actual system performance depends on measurement accuracy and load characteristics.