1. What is the Power Equation?

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

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 is proportional to the square of the voltage and inversely proportional to the resistance.

3. Importance of Power Calculation

Details: Calculating power is essential for designing electrical circuits, determining component ratings, and ensuring safe operation of electrical devices.

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: What if I know current instead of voltage?
A: You can use P = I²R if you know current (I) and resistance, or P = IV if you know current and voltage.

Q2: What are typical power values for household devices?
A: Small electronics might use 1-50W, while appliances like microwaves use 600-1500W.

Q3: Does this work for AC circuits?
A: For AC, you would typically use RMS voltage values in this calculation.

Q4: What happens if resistance is zero?
A: In theory, power would approach infinity (short circuit). In practice, all real circuits have some resistance.

Q5: How does this relate to energy consumption?
A: Energy is power multiplied by time (E = Pt). To calculate energy costs, multiply by hours of use and electricity rate.