1. What is the Power Equation?

The power equation P = V²/R calculates the power dissipation in an electrical circuit based on voltage and resistance. This fundamental relationship is derived from Ohm's Law and Joule's first law.

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)

Explanation: The equation shows that power dissipation increases with the square of the voltage and decreases with higher resistance.

3. Importance of Power Calculation

Details: Calculating power dissipation is crucial for designing circuits, selecting appropriate components, and ensuring safe operation without overheating.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What happens if resistance is zero?
A: The equation becomes undefined (division by zero), representing a short circuit condition with theoretically infinite current.

Q2: How does power change with voltage?
A: Power increases with the square of voltage. Doubling voltage quadruples power dissipation.

Q3: What are typical power ratings for resistors?
A: Common ratings include 1/8W, 1/4W, 1/2W, 1W, and higher for power applications.

Q4: Does this apply to AC circuits?
A: For AC, use RMS voltage values. The equation works for both DC and AC resistive loads.

Q5: What if I know current instead of voltage?
A: Use P = I²R if you know current, or P = VI if you know both voltage and current.