1. What is the Power Formula?

The power formula (P = V × I × PF) calculates the real power in an electrical circuit, accounting for both voltage and current as well as the power factor which represents the phase difference between voltage and current in AC 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, between 0 and 1)

Explanation: The formula calculates real power by multiplying voltage and current, then adjusting for the power factor which accounts for phase differences in AC circuits.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for electrical system design, energy efficiency analysis, circuit protection sizing, and determining energy consumption.

4. Using the Calculator

Tips: Enter voltage in volts, current in amperes, and power factor (between 0 and 1). For DC circuits or purely resistive AC loads, use 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 an AC circuit, representing how effectively current is being converted into useful work.

Q2: When should I use PF = 1?
A: Use PF = 1 for DC circuits or purely resistive AC loads (like incandescent lights or heaters) where voltage and current are in phase.

Q3: What are typical power factor values?
A: Induction motors: 0.8-0.9, fluorescent lights: 0.7-0.9, computers: 0.6-0.7. Power factors below 0.9 may require correction.

Q4: How does power factor affect energy bills?
A: Some utilities charge penalties for low power factor (<0.9) as it increases current requirements without delivering more useful power.

Q5: What's the difference between real, apparent, and reactive power?
A: Real power (P) does useful work, apparent power (S = V×I) is the product of voltage and current, and reactive power (Q) is the non-working power caused by phase shifts.