What is the unit of electrical resistance?

The unit of electrical resistance is the Ohm. This is defined as the resistance that allows a current of one ampere to flow when a voltage of one volt is applied across the resistance. Essentially, the Ohm quantifies how much a material opposes the flow of electric current. According to Ohm's Law, which states that voltage equals current multiplied by resistance (V = I × R), the relationship between voltage, current, and resistance is foundational to understanding electrical circuits.

Other options listed are units of different electrical properties. For instance, the Farad measures capacitance, which is the ability of a component to store an electrical charge. The Watt represents power, indicating the rate at which electrical energy is consumed or generated. The Volt measures electric potential or electromotive force. Each of these units serves its role within the context of electricity, but when it comes to resistance specifically, the Ohm is the correct and definitive unit.