1. What is Resistor Power?

Resistor power refers to the amount of electrical energy converted to heat per second in a resistor. It's crucial for selecting resistors with appropriate power ratings to prevent overheating and failure.

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)
• \( R \) — Resistance in ohms (Ω)

Explanation: The power dissipated in a resistor increases with the square of the voltage and decreases with higher resistance values.

3. Importance of Power Calculation

Details: Calculating resistor power is essential for circuit design to ensure components operate within their thermal limits and maintain reliability.

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 dissipation in watts.

5. Frequently Asked Questions (FAQ)

Q1: What happens if a resistor exceeds its power rating?
A: The resistor may overheat, potentially causing failure, fire hazard, or circuit malfunction.

Q2: How do I select the right resistor power rating?
A: Choose a resistor with a power rating at least 2 times the calculated dissipation for safety margin.

Q3: Does this formula work for AC circuits?
A: For AC, use RMS voltage values. The formula works for both DC and AC (with RMS values).

Q4: What if I know current instead of voltage?
A: Use P = I²R if you know current (I) and resistance, or P = VI if you know voltage and current.

Q5: Why does power increase with voltage squared?
A: Because both current (V/R) and voltage increase together, resulting in V × (V/R) = V²/R.