Ohm's Law Wheel

A visual representation of the relationships between voltage (V), current (I), resistance (R), and power (P). Named after German physicist Georg Ohm, this fundamental law is essential for electrical engineering calculations.

Ohm's Law Wheel diagram with four quadrants showing V, I, R, and P relationships with formulas

Ohm's Law Formulas:

  • Voltage (V): V = I × R (Volts)
  • Current (I): I = V ÷ R (Amperes)
  • Resistance (R): R = V ÷ I (Ohms)
  • Power (P): P = V × I = I² × R = V² ÷ R (Watts)
Quick Example:

If you have a 12V battery and a 4Ω resistor:

Current: I = V ÷ R = 12V ÷ 4Ω = 3A

Power: P = V × I = 12V × 3A = 36W

The Ohm's Law Wheel is a visual aid that helps remember the relationships between electrical quantities.

How to Use the Wheel:

  1. Determine which electrical quantity you need to find (Voltage V, Current I, Resistance R, or Power P)
  2. Locate and cover that quantity on the wheel with your finger
  3. The remaining visible elements will reveal the appropriate formula
  4. Insert your known values into the formula
  5. Calculate to obtain your answer
Try our Ohm's Law Calculator →