Ohm’s Law

Ohm's Law

Remember back to the slope of the stream? This affects the rate at which water flows through the stream. Just like in the stream, the Voltage, Resistance, and Current are all related. 

Back in the early 1800s, a German physicist named Georg Ohm created an equation to express the relationship between current, resistance, and voltage. We call this Ohm’s Law!

To use the Ohm’s Law triangle, we need to know what each letter stands for. V stands for Voltage. R stands for Resistance, and I stands for the French word for intensity or Current. 

If you want to find Voltage, cover that part of the triangle up and you have I next to R. Think about that as I*R. So V=I*R. 

If you want to find Current, cover that part of the triangle up, and you have V over R, which would be V/R. So I=V/R.

If you want to find Resistance, cover that part of the triangle up, and you have V over I, which would be V/I. So R=V/I.

As an example, suppose you want to find the Resistance in a circuit. If you know the Voltage is 110 volts and the Current is 10 amps. So you take 110 volts/10 amps to find a Resistance of 11 Ohms!