What unit is used to measure electrical resistance?

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

Answer: (C)

The unit used to measure electrical resistance is the Ohm. In electrical circuits, resistance quantifies how much a component impedes the flow of electric current. The concept of resistance is rooted in Ohm's Law, which states that the current through a conductor between two points is directly proportional to the voltage across the two points and inversely proportional to the resistance. Thus, if you know the voltage and the current, you can calculate the resistance using the formula:

Resistance (R) = Voltage (V) / Current (I).

The Ohm is defined as the amount of resistance that allows one ampere of current to flow when one volt is applied across it. This unit is foundational in understanding and analyzing electrical circuits, making it essential knowledge in the field of electronics and electrical engineering.