Which unit is used to measure electrical resistance?

• A. Volt (V)
• B. Ampere (A)
• C. Ohm (Ω)
• D. Watt (W)

Answer: (C)

The unit used to measure electrical resistance is the Ohm (Ω). Resistance is a fundamental property in electrical circuits that quantifies how much a material opposes the flow of electric current. According to Ohm's Law, resistance (R) is defined as the voltage (V) across a conductor divided by the current (I) flowing through it, expressed in the formula R = V/I. The Ohm is named after the German physicist Georg Simon Ohm, who studied the relationship between voltage, current, and resistance.

In contrast, the other units mentioned serve different purposes in electrical measurements. The Volt is the unit of electric potential, the Ampere measures electric current, and the Watt quantifies electrical power. Each of these units plays a vital role in understanding and analyzing electrical systems, but when it comes specifically to measuring resistance, the Ohm is the standard unit used.