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The power calculation formula P = V × I is a fundamental equation in electrical engineering that calculates electrical power in watts. It represents the rate at which electrical energy is transferred by an electric circuit.
The calculator uses the power formula:
Where:
Explanation: This formula calculates the electrical power consumed or produced in a circuit by multiplying the voltage across the circuit by the current flowing through it.
Details: Accurate power calculation is essential for circuit design, energy consumption analysis, electrical safety assessments, and determining the capacity requirements for electrical components and systems.
Tips: Enter voltage in volts and current in amperes. Both values must be positive numbers greater than zero for accurate calculation.
Q1: What is the difference between AC and DC power calculation?
A: For DC circuits, P = V × I directly applies. For AC circuits with resistive loads, it's the same, but with reactive loads, power factor must be considered (P = V × I × PF).
Q2: How is this related to energy consumption?
A: Power (watts) multiplied by time (hours) gives energy consumption in watt-hours. For example, 100W device running for 10 hours consumes 1,000 watt-hours (1 kWh).
Q3: What are typical power values for household appliances?
A: LED bulb: 5-15W, Laptop: 30-90W, Refrigerator: 100-400W, Microwave: 600-1200W, Electric heater: 1000-1500W.
Q4: Can this formula be used for three-phase systems?
A: For balanced three-phase systems, power is calculated as P = √3 × V × I × PF, where V is line voltage and I is line current.
Q5: What safety considerations are important?
A: Always ensure circuits are properly rated for calculated power. Overloaded circuits can cause overheating, fire hazards, and equipment damage.