1. What is the Power Equation?

The basic electrical power formula (P = V × I) calculates power in watts by multiplying voltage (in volts) by current (in amps). 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 circuit design, energy consumption estimation, selecting appropriate wire sizes, and determining power supply requirements.

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: For DC circuits or purely resistive AC loads, watts and volt-amps are equal. For reactive loads, they differ due to power factor.

Q2: How do I calculate power for three-phase systems?
A: For three-phase, use P = √3 × V × I × PF (where PF is power factor).

Q3: Can I use this for AC circuits?
A: This gives apparent power for AC. For true power, multiply by power factor (P = V × I × PF).

Q4: What's a typical current for household appliances?
A: Small appliances might draw 1-5A, while larger ones (ovens, dryers) can draw 15-30A at 240V.

Q5: How does this relate to energy consumption?
A: Energy (kWh) = Power (kW) × Time (hours). Multiply watts by hours of use and divide by 1000 for kWh.