1. What is Power Dissipation?

Power dissipation in a resistor refers to the process by which electrical energy is converted to heat energy when current flows through a resistance. This is an important consideration in circuit design to prevent overheating.

2. How Does the Calculator Work?

The calculator uses the power dissipation formula:

Where:

• \( P \) — Power in watts (W)
• \( I \) — Current in amperes (A)
• \( R \) — Resistance in ohms (Ω)

Explanation: The power dissipated by a resistor is proportional to the square of the current flowing through it and directly proportional to its resistance.

3. Importance of Power Calculation

Details: Calculating power dissipation is crucial for selecting properly rated components, preventing overheating, and ensuring circuit reliability. Exceeding a resistor's power rating can lead to failure or fire hazard.

4. Using the Calculator

Tips: Enter current in amperes and resistance in ohms. All values must be positive numbers. The result shows the power dissipation in watts.

5. Frequently Asked Questions (FAQ)

Q1: What happens if power dissipation is too high?
A: The resistor may overheat, change value, or fail completely. In extreme cases, it can cause burns or fire.

Q2: How do I select a resistor based on power calculations?
A: Choose a resistor with a power rating at least 2 times higher than your calculated dissipation for safety margin.

Q3: Does this formula work for AC circuits?
A: Yes, but use RMS current values for AC circuits. The formula applies to instantaneous power in any case.

Q4: What if I know voltage instead of current?
A: Use P = V²/R or P = V×I formulas instead. Different calculators are available for those cases.

Q5: Why does power depend on current squared?
A: Because both voltage drop across the resistor (V=I×R) and power (P=V×I) depend on current, resulting in I² relationship.