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 dissipated (Watts)
• \( V \) — Voltage across the resistor (Volts)
• \( R \) — Resistance (Ohms)

Explanation: The power dissipated by a resistor is equal to the square of the voltage across it divided by its resistance.

3. Importance of Power Calculation

Details: Calculating power dissipation is crucial for selecting resistors with appropriate power ratings, preventing component failure, and ensuring circuit reliability.

4. Using the Calculator

Tips: Enter voltage in volts and resistance in ohms. Both values must be positive numbers (resistance must be greater than zero).

5. Frequently Asked Questions (FAQ)

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

Q2: Are there other power formulas?
A: Yes, power can also be calculated as P = I²R (current squared times resistance) or P = VI (voltage times current).

Q3: What's a typical resistor power rating?
A: Common ratings are 1/8W, 1/4W, 1/2W, and 1W, with higher ratings available for power applications.

Q4: Does power dissipation affect resistance?
A: Most resistors have some temperature coefficient - their value may change slightly as they heat up from power dissipation.

Q5: How is this related to Ohm's Law?
A: The power formula is derived from Ohm's Law (V = IR) combined with the basic power definition (P = VI).