1. What is the Power Equation?

The electrical power equation (P = V × I) calculates power in watts from voltage and current. This fundamental relationship in electrical engineering is known as Joule's first law.

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. Doubling either voltage or current will double the power.

3. Importance of Power Calculation

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

4. Using the Calculator

Tips: Enter voltage in volts and current in amps. Both values must be positive numbers. The calculator will compute the power in watts.

5. Frequently Asked Questions (FAQ)

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

Q2: Can I calculate current if I know voltage and power?
A: Yes, you can rearrange the formula: I = P / V. Similarly, V = P / I.

Q3: What are typical household voltages?
A: In North America, 120V is standard for most outlets, while Europe uses 230V. Large appliances may use 240V (North America) or 400V (Europe).

Q4: How does this relate to energy consumption?
A: Energy (in watt-hours) = Power (watts) × Time (hours). Utility bills are based on energy consumption (kWh).

Q5: What about three-phase power calculations?
A: Three-phase power uses a different formula: P = √3 × V × I × PF (where PF is power factor).