1. What is Power Calculation?

Power calculation in electrical circuits determines the rate at which electrical energy is transferred by an electric circuit. The basic formula P = V²/R calculates power in watts when voltage and resistance are known.

2. How Does the Calculator Work?

The calculator uses the power equation:

Where:

• \( P \) — Power in watts (W)
• \( V \) — Voltage in volts (V)
• \( R \) — Resistance in ohms (Ω)

Note: For AC circuits, frequency (Hz) is included for reference but doesn't affect the power calculation in resistive loads.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for circuit design, component selection, energy efficiency analysis, and electrical safety considerations.

4. Using the Calculator

Tips: Enter voltage in volts, resistance in ohms, and optionally frequency in hertz for AC circuits. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is frequency included for AC circuits?
A: While frequency doesn't affect power calculation in purely resistive loads, it's included for reference in AC circuit analysis.

Q2: Does this formula work for both AC and DC circuits?
A: Yes, P = V²/R works for both AC and DC circuits when dealing with resistive loads.

Q3: What if I have capacitive or inductive components?
A: For reactive loads, additional calculations involving power factor are needed to determine true power.

Q4: How accurate is this calculation?
A: The calculation is mathematically precise for ideal resistive circuits. Real-world factors like temperature effects on resistance may cause variations.

Q5: Can I use this for three-phase power calculations?
A: Three-phase power calculations require different formulas that account for phase relationships and line/phase voltages.