1. What is Electrical Power?

Electrical power is the rate at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt (W), which is equal to one joule per second. In AC circuits, power factor accounts for phase difference between voltage and current.

2. How Does the Calculator Work?

The calculator uses the electrical power formula:

Where:

• \( W \) — Power in watts (W)
• \( V \) — Voltage in volts (V)
• \( A \) — Current in amperes (A)
• \( PF \) — Power factor (unitless, between 0 and 1)

Explanation: For DC circuits, power factor is 1. For AC circuits, power factor represents the phase difference between voltage and current.

3. Importance of Power Calculation

Details: Calculating electrical power is essential for circuit design, energy consumption estimation, electrical safety, and proper sizing of electrical components.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between real power and apparent power?
A: Real power (W) is the actual power consumed, while apparent power (VA) is the product of RMS voltage and current. They're equal only when PF=1.

Q2: Why is power factor important?
A: Low power factor means more current is needed to deliver the same real power, increasing energy losses in distribution systems.

Q3: What's a typical power factor value?
A: For residential loads, PF is typically 0.95-1. Industrial motors might have PF as low as 0.7 without correction.

Q4: How do I improve power factor?
A: Power factor correction capacitors can be added to counteract inductive loads (motors, transformers).

Q5: Does this formula work for three-phase power?
A: For balanced three-phase systems, multiply by √3 (use \( W = \sqrt{3} \times V \times A \times PF \)).