1. What is Power in a Circuit?

Power in an electrical circuit represents the rate at which electrical energy is transferred by an electric circuit. It's measured in watts (W) and calculated using voltage, current, and power factor.

2. How Does the Calculator Work?

The calculator uses the power formula:

For three-phase circuits:

Where:

• \( P \) — Power in watts (W)
• \( V \) — Voltage in volts (V)
• \( I \) — Current in amperes (A)
• \( PF \) — Power factor (unitless, between 0 and 1)
• \( \sqrt{3} \) — Approximately 1.732, used for three-phase calculations

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

3. Importance of Power Calculation

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

4. Using the Calculator

Tips: Enter voltage in volts, current in amperes, and power factor (0 to 1). Select single-phase or three-phase system. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is power factor?
A: Power factor is the ratio of real power to apparent power, representing how effectively current is being converted into useful work.

Q2: What's the difference between single-phase and three-phase?
A: Single-phase has one alternating voltage, common in homes. Three-phase has three voltages offset by 120°, used in industrial applications for efficiency.

Q3: What is a typical power factor value?
A: For purely resistive loads (like heaters), PF=1. For inductive loads (like motors), PF is typically 0.8-0.95 unless corrected.

Q4: Why multiply by √3 for three-phase?
A: The √3 accounts for the phase difference between the three voltage waveforms in a balanced three-phase system.

Q5: Can I use this for DC circuits?
A: Yes, for DC circuits just set PF=1 (since there's no phase difference in DC) and use single-phase calculation.