1. What is the Power Formula?

The power formula P = V × I calculates electrical power in watts, where P represents power, V represents voltage, and I represents current. This fundamental equation is used to determine the rate at which electrical energy is transferred by an electric circuit.

2. How Does the Calculator Work?

The calculator uses the power formula:

Where:

• \( P \) — Electrical power (watts)
• \( V \) — Voltage (volts)
• \( I \) — Current (amps)

Explanation: This formula expresses the relationship between voltage, current, and power in electrical circuits, following Ohm's law principles.

3. Importance of Power Calculation

Details: Calculating electrical power is essential for circuit design, energy consumption analysis, electrical safety assessments, and determining the capacity requirements for electrical components and systems.

4. Using the Calculator

Tips: Enter voltage in volts and current in amps. Both values must be positive numbers greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between AC and DC power calculation?
A: For DC circuits, P = V × I directly. For AC circuits with resistive loads, it's the same, but with reactive loads, power factor must be considered.

Q2: How is this related to Ohm's Law?
A: When combined with Ohm's Law (V = I × R), the power formula can also be expressed as P = I² × R or P = V² ÷ R.

Q3: What are typical power values in household appliances?
A: Household appliances range from small electronics (5-50W) to major appliances like refrigerators (100-800W) and air conditioners (1000-5000W).

Q4: Can this formula be used for three-phase systems?
A: For three-phase systems, the formula becomes P = √3 × V × I × PF, where PF is the power factor.

Q5: Why is power measured in watts?
A: Watts represent the rate of energy transfer - one watt equals one joule per second, named after James Watt for his work on steam engine efficiency.