This site will look much better in a browser that supports web standards, but it is accessible to any browser or Internet device.

Ag Power Web Enhanced Course Materials

If you experience any problems with the site, please contact Pete Hoffman immediately so corrections can be made. Pete can be reached on campus, via email at or by phone at 1.800.362.3322 ext 2727.

Ohm's Law - Calculating Voltage

What is Voltage (E)?

Voltage is the potential difference in a circuit and it is caused by the unbalanced state of atoms. You need a complete circuit made of conductive material in order to have current flow and the current will flow from the negative source to the positive source. Ohms law states that if you have one volt applied to a one ohm resistance the current will be one amp.

Voltage Equation

(E = I x R)

Voltage (E) on the equation is missing and you have the (I) and (R) left. Because they are divided by the vertical line that means to multiply the two values.
Simple Circuit

This is a simple circuit with a current of 12 amps (12A) and a resistive load of 1 Ohm (1). Use the formula explained on the left side of the page to calculate the voltage.

Since we know the battery is suppling 12 Amps (I), and there is a resistive load of 1 Ohm (R) placed in series, the current will be:

E = 12(I) times 1(R) or E = 12

Click the term to see examples of Current and Resistance.