How is electrical resistance measured?

Electrical resistance is measured in ohms (Ω), which is the standard unit in the International System of Units (SI) for quantifying how much a conductor opposes the flow of electric current. Ohm’s law defines the relationship between voltage (volts), current (amps), and resistance (ohms) with the formula V = I × R, where V represents voltage, I is current, and R is resistance. This law illustrates that resistance is crucial in determining how much current will flow in a circuit when a certain voltage is applied. Understanding this concept is fundamental in electrical engineering and is particularly important in applications involving circuits, like those found in elevators and various electrical devices.

Other choices represent different electrical quantities: volts refer to voltage, amps refer to electric current, and watts refer to power, which is a measure of the rate of energy transfer. Each of these plays a role in electrical circuits, but only ohms specifically quantifies resistance.