1. What is AC Power?

AC power is the rate at which electrical energy is transferred by an alternating current circuit. In AC systems, the power factor (cos φ) accounts for the phase difference between voltage and current.

2. How Does the Calculator Work?

The calculator uses the AC power formula:

Where:

• \( P \) — Real power in watts (W)
• \( V \) — RMS voltage in volts (V)
• \( I \) — RMS current in amperes (A)
• \( \cos(\phi) \) — Power factor (dimensionless, 0 to 1)

Explanation: This formula calculates the real (useful) power in an AC circuit, accounting for the phase difference between voltage and current.

3. Importance of Power Factor

Details: Power factor indicates how effectively electrical power is being used. A lower power factor means more current is required to deliver the same amount of real power.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What is 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 power that oscillates between source and load.

Q2: What causes low power factor?
A: Inductive loads like motors and transformers cause current to lag voltage, reducing power factor. Capacitors can correct this.

Q3: What is a typical power factor value?
A: Residential: ~0.95-1.0, Industrial: ~0.8-0.9. Pure resistive loads have pf=1, inductive loads have pf<1.

Q4: Why is power factor important?
A: Utilities often charge industries for low power factor as it increases transmission losses and requires larger equipment.

Q5: How can power factor be improved?
A: Adding capacitors (power factor correction), using synchronous motors, or reducing idle running of inductive equipment.