1. What is AC Power?

AC power in watts is the real power consumed by an electrical circuit, calculated as the product of voltage, current, and power factor. It represents the actual work-performing capacity of the electrical energy.

2. How Does the Calculator Work?

The calculator uses the AC power formula:

Where:

• \( P \) — Real power in watts
• \( V \) — Voltage in volts
• \( I \) — Current in amperes
• \( \cos\varphi \) — Power factor (unitless, between 0 and 1)

Explanation: The formula accounts for the phase difference between voltage and current in AC circuits through the power factor.

3. Importance of Power Factor

Details: Power factor represents the efficiency of power usage. A higher power factor (closer to 1) means more efficient power transfer, while lower values indicate reactive power losses.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, and power factor (decimal between 0 and 1). All values must be valid (voltage > 0, current > 0, 0 ≤ power factor ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between real power and apparent power?
A: Real power (watts) performs actual work, while apparent power (VA) is the product of voltage and current without considering power factor.

Q2: What is a typical power factor value?
A: Residential: 0.95-1.0, Industrial: 0.8-0.9, Motors at full load: ~0.85. Pure resistive loads have PF=1.

Q3: How can power factor be improved?
A: Using power factor correction capacitors, synchronous condensers, or avoiding lightly loaded motors.

Q4: Does this formula work for DC circuits?
A: For DC, power factor is always 1, so the formula simplifies to P = V × I.

Q5: Why is power factor important for utilities?
A: Utilities often charge penalties for low power factor because it increases current and energy losses in distribution systems.