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 relationship between voltage, current, and power in a 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 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 and wiring.

4. Using the Calculator

Tips: Enter voltage in volts and current in amps. Typical household voltage is 120V in North America and 230V in many other countries. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between watts and volt-amps?
A: For DC circuits or purely resistive AC loads, they're the same. For reactive loads, apparent power (VA) differs from real power (W) due to power factor.

Q2: How many watts is 120 amps at 120 volts?
A: 14,400 watts (120V × 120A = 14,400W).

Q3: Can I use this for three-phase power calculations?
A: For balanced three-phase systems, you would multiply by √3 (about 1.732) to account for phase relationships.

Q4: Why does power matter in electrical systems?
A: Power determines energy consumption (kWh), heat generation, and the capacity requirements for wires, breakers, and other components.

Q5: How does this relate to circuit breakers?
A: Circuit breakers are rated for current (amps), but the actual power (watts) they can handle depends on the voltage of the circuit.