What is the unit of electrical resistance?

The unit of electrical resistance is the Ohm, represented by the symbol (Ω). Resistance is a measure of how much an object opposes the flow of electric current. The relationship between voltage (the electric potential) and current (the flow of electric charge) through a conductor is defined by Ohm's Law, which states that V = IR, where V is voltage, I is current, and R is resistance. Therefore, when resistance increases, the current decreases for a given voltage, and this relationship is fundamental to understanding electrical circuits.

The other choices represent different electrical quantities: the Watt is the unit of power, which measures the rate of energy transfer; the Volt is the unit of electric potential or voltage; and the Ampere is the unit of electric current. Each of these plays a crucial role in electrical theory and practice, but they denote different aspects of electrical systems rather than resistance itself.