The unit of measure of electrical resistance is

• A. Volts
• B. Amperes
• C. Ohms
• D. Watts

Answer: (C)

Resistance is a property that describes how much a component slows down electric current. The unit used to measure that property is the ohm. An ohm is defined as the resistance between two points of a conductor when a constant potential difference of one volt, applied to those points, produces a current of one ampere. So, if you know the voltage and the current, you can use R = V / I, which yields the unit of volts per ampere, defined as one ohm. In everyday terms, higher resistance means less current for the same voltage. Volts measure electric potential, amperes measure current, and watts measure power, none of which is resistance itself. That’s why the unit for resistance is ohms.