Home
Back
Power Formula:
| From: | To: |
The power equation P = V × I is a fundamental formula in electrical engineering that calculates electrical power from voltage and current measurements. It represents the rate at which electrical energy is transferred by an electric circuit.
The calculator uses the power equation:
Where:
Explanation: This 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, energy consumption analysis, electrical safety assessments, and determining appropriate component ratings in electrical systems.
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 applies directly. For AC circuits, additional factors like power factor must be considered for accurate power calculation.
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 household appliances range from 5-10W (LED bulbs) to 1500-3000W (heaters, air conditioners), with most electronics consuming 50-500W.
Q4: Why is power calculation important for electrical safety?
A: Calculating power helps determine appropriate wire sizes, circuit breaker ratings, and ensures electrical systems operate within safe limits to prevent overheating and fire hazards.
Q5: 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.