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Power Formula:
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The power formula (P = V × I × PF) calculates electrical power in watts (W) by multiplying voltage (V), current (I), and power factor (PF). This is fundamental in electrical engineering and circuit analysis.
The calculator uses the power formula:
Where:
Explanation: For DC circuits or AC circuits with purely resistive loads, the power factor is 1. For AC circuits with reactive components, the power factor represents the phase difference between voltage and current.
Details: Accurate power calculation is essential for designing electrical systems, selecting appropriate components, calculating energy consumption, and ensuring electrical safety.
Tips: Enter voltage in volts, current in amperes, and power factor (between 0 and 1). All values must be valid (voltage > 0, current > 0, 0 ≤ PF ≤ 1).
Q1: What is power factor?
A: Power factor is the ratio of real power flowing to the load to the apparent power in the circuit. It ranges from 0 to 1, with 1 being most efficient.
Q2: When should I use power factor = 1?
A: Use PF=1 for DC circuits or purely resistive AC loads (like incandescent lights or heaters). For inductive or capacitive loads (motors, transformers), PF is typically less than 1.
Q3: What are typical power factor values?
A: Residential: 0.95-1.0, Industrial: 0.7-0.9, Motors at full load: 0.8-0.9, Transformers: 0.8-0.98.
Q4: How does power factor affect energy bills?
A: Many utilities charge commercial customers extra for low power factor (typically below 0.9) because it increases current requirements without delivering more useful power.
Q5: Can power factor be greater than 1?
A: No, power factor is always between 0 and 1. Values above 1 would indicate measurement errors or non-sinusoidal waveforms.