Voltage Current Resistor Wattage Calculator

Power Formula:

\[ P = \frac{V^2}{R} \]

Power (P): watts

Current (I): amps

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1. What is a Voltage Current Resistor Wattage Calculator?

Definition: This calculator determines the power dissipation in a resistor and the current flowing through it based on Ohm's Law and the power formula.

Purpose: It helps electrical engineers, technicians, and hobbyists design and analyze circuits by calculating key electrical parameters.

2. How Does the Calculator Work?

The calculator uses two fundamental formulas:

\[ P = \frac{V^2}{R} \] \[ I = \frac{V}{R} \]

Where:

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

Explanation: The voltage squared divided by resistance gives power dissipation, while voltage divided by resistance gives current.

3. Importance of Power Calculation

Details: Proper power calculation ensures resistors are appropriately sized to handle the power dissipation without overheating or failing.

4. Using the Calculator

Tips: Enter the voltage across the resistor and its resistance value. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What happens if my resistor can't handle the calculated power?
A: The resistor may overheat and fail. Always use resistors with wattage ratings higher than the calculated power.

Q2: Can I use this for AC circuits?
A: Yes, if you use RMS voltage values for AC circuits.

Q3: What's the relationship between power, voltage, and current?
A: Power also equals voltage times current (P = V × I), which is equivalent to V²/R through Ohm's Law.

Q4: Why does power increase with voltage squared?
A: Because both current and voltage increase with higher voltage (per Ohm's Law), leading to a squared relationship in power.

Q5: How do I measure resistance?
A: Use a multimeter in resistance mode or check the resistor's color code if available.