What is the unit of electrical resistance?

• A. Ampere
• B. Volt
• C. Ohm
• D. Watt

Answer: (C)

The main concept is how resistance is quantified in circuits. Resistance measures how much a component opposes current flow. The standard unit is the ohm, symbolized by the Greek letter Omega. This unit arises from Ohm’s law, V = I × R, which means resistance equals voltage divided by current. One 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. That makes the ohm the natural unit for expressing how much a component resists current.

Ampere is the unit of current, volt is the unit of electric potential difference, and watt is the unit of power, so they describe other aspects of electrical behavior rather than resistance itself.