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Current Formula:
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The current formula (I = P/V) calculates electrical current in amperes from power in watts and voltage in volts. This fundamental relationship is derived from Ohm's Law and is essential in electrical engineering and circuit design.
The calculator uses the basic electrical formula:
Where:
Explanation: The formula shows that current is directly proportional to power and inversely proportional to voltage. Higher power at the same voltage means more current, while higher voltage with the same power means less current.
Details: Calculating current is crucial for designing electrical circuits, selecting appropriate wire gauges, determining fuse sizes, and ensuring electrical safety. It helps prevent circuit overloads and potential fire hazards.
Tips: Enter power in watts and voltage in volts. Both values must be positive numbers. The calculator will compute the current in amperes.
Q1: What's the difference between AC and DC current in this calculation?
A: For purely resistive loads, the formula works the same for both AC and DC. For AC with reactive components, you would need to consider power factor.
Q2: How does this relate to Ohm's Law?
A: This is a power-based version of Ohm's Law. The traditional form is I = V/R, but when you substitute P = V²/R, you get I = P/V.
Q3: What are typical current values in household circuits?
A: Standard household circuits in the US (120V) are typically 15A or 20A. Higher power appliances like electric stoves may use 240V at 30-50A.
Q4: Why is current calculation important for wiring?
A: Wire gauge must be selected based on current to prevent overheating. Higher currents require thicker wires to safely carry the load.
Q5: Can I use this for three-phase current calculation?
A: For three-phase systems, you would need to include the power factor and use the formula I = P / (√3 × V × PF).