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 and load requirements.

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: The formula shows that power is the product of voltage and current, adjusted by the power factor which accounts for phase differences in AC circuits.

3. Importance of Power Calculation

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

4. Using the Calculator

Tips: Enter voltage in volts, current in amperes, and power factor (between 0 and 1). For DC circuits, use PF=1. 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 efficiency of power usage. It's 1 for DC circuits and typically 0.8-0.95 for AC circuits.

Q2: Why is power factor important?
A: Low power factor increases current requirements and energy losses in distribution systems. Utilities often charge penalties for low power factor.

Q3: What's the difference between real, reactive and apparent power?
A: Real power (P) does actual work, reactive power (Q) sustains electromagnetic fields, and apparent power (S) is the vector sum of P and Q (S = √(P² + Q²)).

Q4: How does this apply to three-phase systems?
A: For three-phase, multiply by √3 (P = √3 × V × I × PF). Our calculator is for single-phase systems.

Q5: Can I use this for DC circuits?
A: Yes, for DC simply set PF=1 (since there's no phase difference between voltage and current).