1. What is the Electric Power Equation?

The electric power equation (P = V × I) calculates the power consumption of an electrical device or motor based on the voltage applied and the current drawn. This fundamental relationship is known as Joule's first law.

2. How Does the Calculator Work?

The calculator uses the electric power equation:

Where:

• \( P \) — Power in watts (W)
• \( V \) — Voltage in volts (V)
• \( I \) — Current in amperes (A)

Explanation: The power consumed by an electrical device is directly proportional to both the voltage applied and the current drawn.

3. Importance of Power Calculation

Details: Calculating power consumption is essential for sizing electrical components, determining energy usage, selecting appropriate wiring, and ensuring electrical safety in motor applications.

4. Using the Calculator

Tips: Enter voltage in volts and current in amps. Both values must be positive numbers. The calculator will compute the power in watts.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between real power and apparent power?
A: This calculator shows real power (watts). Apparent power (VA) includes reactive power and is calculated as V × I without power factor consideration.

Q2: How does this apply to three-phase motors?
A: For three-phase systems, the formula becomes P = √3 × V × I × PF, where PF is power factor (typically 0.8-0.9 for motors).

Q3: What are typical voltage and current values for motors?
A: Small motors might run on 12V/5A (60W), while industrial motors could be 480V/100A (48kW).

Q4: How can I measure voltage and current?
A: Use a multimeter - measure voltage across terminals and current in series with the circuit.

Q5: What about motor efficiency?
A: This calculates input power. Output power would be less due to efficiency losses (typically 70-95% for electric motors).