1. What is the Power Equation?

The power equation P = V × I is a fundamental formula in electrical engineering that calculates electrical power from voltage and current measurements. It represents the rate at which electrical energy is transferred by an electric circuit.

2. How Does the Calculator Work?

The calculator uses the power equation:

Where:

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

Explanation: This equation demonstrates the direct proportionality between power and both voltage and current in a DC circuit or the real power in an AC circuit with resistive loads.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for circuit design, energy consumption analysis, electrical system sizing, and determining the capacity requirements for power supplies and electrical components.

4. Using the Calculator

Tips: Enter voltage in volts and current in amperes. Both values must be positive numbers greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: Does this formula work for AC circuits?
A: For purely resistive AC circuits, yes. For circuits with reactive components, additional factors like power factor must be considered.

Q2: What are typical power values in household appliances?
A: Household appliances typically range from a few watts (LED bulbs) to several thousand watts (electric heaters, air conditioners).

Q3: How is this different from apparent power?
A: This formula calculates real power (measured in watts). Apparent power (measured in volt-amperes) includes both real and reactive power components.

Q4: Can I use this for three-phase power calculation?
A: For balanced three-phase systems, the formula becomes P = √3 × V × I × PF, where PF is the power factor.

Q5: What safety considerations should I keep in mind?
A: Always ensure electrical measurements are taken with proper safety equipment and by qualified personnel, especially when working with high voltages or currents.