When voltage and current are known, which formula is used to determine resistance?

The formula used to determine resistance when voltage and current are known is R = E/I. This relationship stems from Ohm's Law, which states that the resistance (R) is equal to the voltage (E) across a circuit divided by the current (I) flowing through it. This foundational principle of electrical engineering illustrates how resistance regulates the flow of electrical current in relation to the applied voltage.

When you rearrange Ohm's Law, you can see that knowing both the voltage (voltage difference) and the current allows you to isolate resistance as a key parameter in understanding electrical circuits. The formula effectively demonstrates how changes in voltage or current will influence the resistance encountered in a circuit, providing insights into how circuits may behave under varying loads.

The other formulas proposed do not align with the relationship defined by Ohm's Law. For example, the formulas that involve multiplication or addition do not represent the linear relationship required to calculate resistance accurately.