1. What is the Power Equation?

The power equation (P = V × I) calculates electrical power in watts from voltage and current. It applies to DC circuits and single-phase AC circuits with resistive loads.

2. How Does the Calculator Work?

The calculator uses the basic power equation:

Where:

• \( P \) — Power in watts (W)
• \( V \) — Voltage in volts (V)
• \( I \) — Current in amperes (A)

Explanation: The equation shows that power is directly proportional to both voltage and current.

3. Importance of Power Calculation

Details: Calculating power is essential for circuit design, electrical safety, energy consumption estimation, and proper component selection.

4. Using the Calculator

Tips: Enter voltage in volts and current in amps. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Does this work for three-phase power?
A: No, for three-phase power you need to include the power factor and use P = √3 × V × I × PF.

Q2: What's the difference between real power and apparent power?
A: Real power (watts) is the actual power consumed, while apparent power (VA) is the product of RMS voltage and current without considering phase angle.

Q3: How does power factor affect the calculation?
A: For AC circuits with reactive components, you need to multiply by the power factor (P = V × I × PF).

Q4: What are typical power ratings for household appliances?
A: Small devices might use 10-100W, while large appliances like ovens or dryers can use 1000-5000W.

Q5: How can I calculate energy consumption from power?
A: Energy (kWh) = Power (kW) × Time (hours). Multiply the result by your electricity rate to estimate cost.