1. What is the Power Equation?

The power equation P = V²/R calculates electrical power in watts from voltage and resistance. This formula is derived from Ohm's law and Joule's law, relating voltage, current, and resistance in electrical circuits.

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: This equation shows that power is proportional to the square of the voltage and inversely proportional to the resistance in a circuit.

3. Importance of Power Calculation

Details: Calculating electrical power is essential for circuit design, energy consumption analysis, component selection, and ensuring electrical safety in various applications.

4. Using the Calculator

Tips: Enter voltage in volts and resistance in ohms. Both values must be positive numbers greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What are the units for power calculation?
A: Power is measured in watts (W), voltage in volts (V), and resistance in ohms (Ω).

Q2: Can this formula be used for AC circuits?
A: This formula applies to DC circuits. For AC circuits, additional factors like power factor must be considered.

Q3: What is the relationship between power, voltage and current?
A: Power can also be calculated as P = V × I, where I is current in amperes.

Q4: Why does power increase with the square of voltage?
A: Because both voltage and current increase with higher voltage (per Ohm's law I = V/R), resulting in squared relationship for power.

Q5: What are typical power values in electrical systems?
A: Power values range from milliwatts (mW) in small electronics to kilowatts (kW) in household appliances and megawatts (MW) in industrial systems.