1. What is the Power Formula?

The power formula (P = V × I) calculates electrical power in watts by multiplying voltage (in volts) by current (in amperes). This fundamental equation is known as Joule's first law or the electrical power formula.

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 electrical power is essential for designing circuits, selecting appropriate components, determining energy consumption, and ensuring electrical safety.

4. Using the Calculator

Tips: Enter current in amperes and voltage in volts. 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: How do I calculate power for three-phase systems?
A: For three-phase systems, use P = √3 × V × I × PF (where PF is power factor).

Q3: Can I use this for AC circuits?
A: For AC circuits with reactive components, you'll need to consider power factor. This calculator is most accurate for DC or purely resistive AC circuits.

Q4: What if I know power and want to find current?
A: Rearrange the formula: I = P / V. This is useful for determining current draw of appliances.

Q5: How does this relate to energy consumption?
A: Energy (in watt-hours) = Power (in watts) × Time (in hours). Power tells you the rate of energy use.