1. What is the Electrical Power Equation?

Definition: This equation calculates the real power in an AC electrical circuit based on voltage, current, and power factor.

Purpose: It helps electricians, engineers, and technicians determine the actual power consumption in AC circuits.

2. How Does the Equation Work?

The equation uses the formula:

Where:

• \( P_w \) — Real power (watts)
• \( V \) — Voltage (volts)
• \( I \) — Current (amps)
• \( PF \) — Power factor (unitless, between 0 and 1)

Explanation: The product of voltage and current gives apparent power, which is then multiplied by the power factor to get real power.

3. Importance of Power Calculation

Details: Accurate power calculation ensures proper circuit design, energy efficiency, and correct sizing of electrical components.

4. Using the Calculator

Tips: Enter the voltage in volts, current in amps, and power factor (default 1.0 for purely resistive loads). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is power factor?
A: Power factor is the ratio of real power to apparent power, representing the phase difference between voltage and current.

Q2: When would power factor be less than 1?
A: In circuits with inductive or capacitive loads (motors, transformers, etc.), typically ranging from 0.7 to 0.95.

Q3: What's the difference between real and apparent power?
A: Real power (watts) does actual work, while apparent power (VA) is the product of voltage and current.

Q4: How do I measure these values?
A: Use a multimeter for voltage and current, and a power meter for power factor.

Q5: Does this work for DC circuits?
A: For DC, the formula simplifies to P = V × I since power factor is always 1.