1. What is the Power Equation?

The power equation \( W = \frac{V^2}{R} \) calculates electrical power in watts from voltage and resistance. It's derived from combining Ohm's Law and the basic power formula.

2. How Does the Calculator Work?

The calculator uses the power equation:

Where:

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

Explanation: The power dissipated in a resistor is proportional to the square of the voltage across it and inversely proportional to its resistance.

3. Importance of Power Calculation

Details: Calculating power is essential for circuit design, determining component ratings, and ensuring electrical safety by preventing 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 in watts.

5. Frequently Asked Questions (FAQ)

Q1: Can this formula be used for AC circuits?
A: Yes, but for AC you would typically use RMS voltage values for accurate power calculations.

Q2: What if I know current instead of resistance?
A: You can use \( W = V \times I \) if you know current (I) instead of resistance.

Q3: What are typical power ratings for household appliances?
A: Small electronics might be 5-50W, while large appliances can be 1000W or more.

Q4: How does power relate to energy?
A: Power is the rate of energy use. Energy (in watt-hours) = Power × Time.

Q5: Why does power increase with voltage squared?
A: Because both current and voltage increase with higher voltage (per Ohm's Law), and power is voltage × current.