National Oilheat Research Alliance (NORA) Bronze Certification Practice Exam

Resistance to the flow of electricity is measured in ohms. This unit quantifies how strongly an object opposes the flow of electric current. The relationship between voltage (measured in volts), current (measured in amps), and resistance (in ohms) is described by 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.

Understanding this concept is essential in electrical applications, including those related to oilheat systems, where managing electrical flow is crucial for safe and efficient operation. Without this measurement, it would be challenging to design and troubleshoot electrical circuits, making the ohm an indispensable unit in both theoretical and practical electrical engineering.