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AC Power Formula:
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The AC Power Formula calculates the real power in an alternating current circuit. Unlike DC circuits where power is simply voltage times current, AC circuits must account for the phase difference between voltage and current, represented by the power factor.
The calculator uses the AC Power formula:
Where:
Explanation: The formula calculates the actual power consumed in an AC circuit, accounting for the phase relationship between voltage and current through the power factor.
Details: Power factor represents the efficiency of power usage in AC systems. A power factor of 1 indicates perfect efficiency, while lower values indicate reactive power that doesn't perform useful work but still requires infrastructure capacity.
Tips: Enter RMS voltage in volts, RMS current in amps, and power factor between 0 and 1. All values must be positive, with power factor in the valid range.
Q1: What is the difference between real power and apparent power?
A: Real power (P) is the actual power consumed and measured in watts. Apparent power (S = V×I) is the product of voltage and current, measured in volt-amperes.
Q2: Why is power factor important in electrical systems?
A: Low power factor increases current for the same real power, requiring larger conductors and transformers, and may result in utility penalties for commercial users.
Q3: What causes low power factor?
A: Inductive loads like motors, transformers, and fluorescent lighting cause current to lag voltage, reducing power factor. Capacitive loads cause current to lead voltage.
Q4: How can power factor be improved?
A: Power factor correction capacitors can be added to counteract inductive loads, bringing power factor closer to 1 and reducing reactive power.
Q5: When is this formula most accurate?
A: This formula works well for sinusoidal AC waveforms. For non-sinusoidal waveforms or circuits with harmonics, additional calculations may be needed.