1. What is the Power Formula?

The power formula P = V² / R calculates electrical power in watts from voltage and resistance. This is derived from combining Ohm's law (V = IR) and the power formula (P = IV).

2. How Does the Calculator Work?

The calculator uses the power formula:

Where:

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

Explanation: The formula shows that power is proportional to the square of the voltage and inversely proportional to the resistance.

3. Importance of Power Calculation

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

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 each variable?
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 works for DC circuits. For AC circuits, you need to consider power factor and use RMS values for accurate calculations.

Q3: What is a typical power range for household appliances?
A: Household appliances typically range from a few watts (LED bulbs) to several thousand watts (electric heaters, ovens).

Q4: How does resistance affect power consumption?
A: Higher resistance generally results in lower power consumption for a given voltage, as power is inversely proportional to resistance.

Q5: What safety considerations should be made with power calculations?
A: Always ensure components can handle the calculated power to prevent overheating, fire hazards, and equipment damage.