Kaplan Nursing Entrance Practice Exam

Which unit is used to measure electrical resistance?

1. Volts

2. Watts

3. Amperes

4. Ohms

The correct answer is: Ohms

The unit used to measure electrical resistance is the ohm. Electrical resistance quantifies how much a material opposes the flow of electric current. In the context of electrical circuits, ohms provide a standard way to convey how much resistance is present in a circuit component or material. The relationship between voltage (volts), current (amperes), and resistance (ohms) is described by Ohm’s Law, which states that the voltage across a conductor is proportional to the current flowing through it, with the resistance acting as the proportionality factor. Therefore, understanding resistance in terms of ohms is fundamental for analyzing and designing electrical circuits. To clarify the other units: volts measure electrical potential or voltage, amperes measure the flow of electric current, and watts measure electrical power, which is the rate at which energy is consumed or transferred. Each of these units plays a distinct role in electrical calculations, but for resistance specifically, ohms are the appropriate measure.