1. What is the Power Equation?

The power equation (P = V × I) calculates electrical power in watts from voltage and current. It's a fundamental equation in electrical engineering and physics that describes the rate of energy transfer in an electrical 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: The equation shows that power is directly proportional to both voltage and current in a circuit.

3. Importance of Power Calculation

Details: Calculating power is essential for circuit design, electrical safety, energy efficiency calculations, and determining appropriate component ratings.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between watts and volt-amps?
A: Watts represent real power, while volt-amps represent apparent power. They're equal in DC circuits or AC circuits with purely resistive loads.

Q2: How does power relate to energy?
A: Power is the rate of energy transfer. Energy (in watt-hours) = Power (in watts) × Time (in hours).

Q3: Can this be used for AC circuits?
A: For AC circuits with purely resistive loads, yes. For reactive loads, power factor must be considered.

Q4: What are typical household appliance power ratings?
A: LED bulbs: 5-20W, Laptop: 50-100W, Microwave: 600-1200W, Refrigerator: 100-400W.

Q5: How can I calculate current from power and voltage?
A: Rearrange the equation: I = P / V (current = power divided by voltage).