1. What is Power Through a Resistor?

Power through a resistor is the rate at which electrical energy is converted to heat and dissipated by the resistor. It's calculated using the formula P = V × I, where P is power in watts, V is voltage across the resistor, and I is current through the resistor.

2. How Does the Calculator Work?

The calculator uses the power equation:

Where:

• \( P \) — Power in watts (W)
• \( V \) — Voltage across the resistor in volts (V)
• \( I \) — Current through the resistor in amperes (A)

Explanation: The power dissipated by a resistor is simply the product of the voltage across it and the current flowing through it.

3. Importance of Power Calculation

Details: Calculating power is essential for selecting resistors with appropriate wattage ratings to prevent overheating and failure. It's also crucial for designing efficient circuits and understanding energy consumption.

4. Using the Calculator

Tips: Enter the voltage across the resistor in volts and the current through the resistor in amperes. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Can I use this for AC circuits?
A: This calculator is for DC circuits. For AC circuits, you would need to consider power factor for accurate calculations.

Q2: What if I only know resistance and current?
A: You can also calculate power using P = I² × R, where R is resistance in ohms.

Q3: What if I only know resistance and voltage?
A: You can use P = V² / R to calculate power in that case.

Q4: What happens if power exceeds resistor rating?
A: The resistor may overheat, potentially causing failure or even fire in extreme cases.

Q5: How do I choose the right resistor wattage?
A: Select a resistor with a wattage rating at least twice your calculated power for safety margin.