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 relates these three basic electrical quantities.

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 designing electrical systems, selecting appropriate wiring and components, determining energy consumption, and ensuring electrical safety.

4. Using the Calculator

Tips: Enter voltage in volts and current in amperes. The calculator defaults to 240 volts (common household voltage in many countries) but can calculate for any voltage. 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 and purely resistive AC loads, watts and volt-amps are equal. For reactive loads, they differ due to power factor.

Q2: How many watts can a 240V 15A circuit handle?
A: 240V × 15A = 3,600 watts (assuming continuous load is limited to 80% of circuit capacity).

Q3: Why is 240V used instead of 120V?
A: Higher voltage allows more power with less current, reducing energy loss in wiring and enabling smaller wire sizes.

Q4: Can I calculate current if I know power and voltage?
A: Yes, rearrange the equation: I = P / V.

Q5: What's the relationship between watts and kilowatt-hours?
A: Kilowatt-hours are watts × time (hours). Energy = Power × Time.