According to Ohm's law, how is resistance expressed in a circuit?

The correct expression for resistance according to Ohm's law is represented as R = E/I. In this formula, R stands for resistance, E represents voltage (often denoted as V in common use), and I represents current. This relationship illustrates that the resistance in a circuit can be calculated by dividing the voltage across the component by the current flowing through it.

Understanding this formula is crucial for working with electrical systems since it helps technicians determine how much resistance is present in a circuit when the voltage and current are known. An increase in resistance usually indicates a decrease in current for a constant voltage, adhering to Ohm's law. Knowing this principle aids technicians in diagnosing issues in electrical circuits and designing systems that function within desired parameters.

The other choices illustrate misunderstandings of the relationships defined by Ohm's law. For example, the expression R = V * I misinterprets how resistance is related to voltage and current. The correct formulation emphasizes that resistance is derived from the ratio of voltage to current, not a product.