1. What is the Power Equation?

The power equation (P = V × I) calculates electrical power in watts from voltage (volts) and current (amperes). This fundamental relationship 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: The equation shows that power is directly proportional to both voltage and current in an electrical circuit.

3. Importance of Power Calculation

Details: Calculating power is essential for circuit design, energy consumption estimation, electrical safety assessments, and proper component selection in electrical systems.

4. Using the Calculator

Tips: Enter voltage in volts and current in amperes. 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 does this relate to energy consumption?
A: Energy (in watt-hours) = Power (watts) × Time (hours). This calculator gives the instantaneous power consumption.

Q3: Can I use this for AC circuits?
A: For AC circuits with purely resistive loads, yes. For reactive loads, you need to consider power factor.

Q4: What are typical household voltages?
A: Common voltages are 120V in North America and 230V in many other countries, though appliances may use different voltages.

Q5: How can I measure current safely?
A: Always use a properly rated multimeter or clamp meter. Never measure current by shorting a voltage source.