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The power equation P = V × I calculates electrical power in watts from voltage (volts) and current (amps). It's a fundamental formula in electrical engineering and physics that describes the relationship between these three basic electrical quantities.
The calculator uses the power equation:
Where:
Explanation: The equation shows that power is directly proportional to both voltage and current. Doubling either voltage or current will double the power output.
Details: Accurate power calculation is essential for circuit design, electrical system planning, energy consumption estimation, and ensuring electrical safety in various applications from household appliances to industrial equipment.
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.
Q2: How does this relate to energy consumption?
A: Power (watts) multiplied by time (hours) gives energy consumption in watt-hours. 1000 watt-hours equals 1 kilowatt-hour (kWh), the standard unit for electricity billing.
Q3: Can this formula be used for three-phase systems?
A: For balanced three-phase systems, the formula becomes P = √3 × V × I × power factor, where V is line voltage and I is line current.
Q4: What are typical power ratings for household appliances?
A: Common household appliances range from 5-10W (LED bulbs) to 1000-3000W (heaters, air conditioners). Always check manufacturer specifications for exact ratings.
Q5: How accurate is this calculation for real-world applications?
A: The formula provides theoretical maximum power. Actual power may vary due to efficiency losses, power factor, and other real-world factors in electrical systems.