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Power Equation:
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The power equation (P = V × I) calculates electrical power in watts from voltage and current measurements. This fundamental formula is derived from Ohm's Law and is essential in electrical engineering and circuit design.
The calculator uses the power equation:
Where:
Explanation: The equation shows that power is directly proportional to both voltage and current. Increasing either voltage or current will increase the power output.
Details: Accurate power calculation is crucial for designing electrical systems, selecting appropriate components, ensuring safety, and optimizing energy efficiency in various applications from household appliances to industrial machinery.
Tips: Enter voltage in volts and current in amperes. Both values must be positive numbers. The calculator will compute the power rating in watts.
Q1: What is the difference between AC and DC power calculations?
A: For DC circuits, P = V × I directly. For AC circuits, you need to consider power factor: P = V × I × PF, where PF is the cosine of the phase angle between voltage and current.
Q2: How does resistance relate to power?
A: Using Ohm's Law (V = I × R), power can also be calculated as P = I² × R or P = V² / R, where R is resistance in ohms.
Q3: What are typical power ratings for household appliances?
A: Common appliances range from 5-10W (LED bulbs) to 1000-3000W (heaters, ovens). Always check manufacturer specifications for accurate ratings.
Q4: Why is power calculation important for circuit design?
A: It helps determine appropriate wire sizes, circuit breaker ratings, and ensures components can handle the expected power without overheating or failing.
Q5: Can this calculator 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.