ABYC Marine Electrical Practice Exam

Which factor is least likely to contribute to electrical resistance?

1. Wire connection quality

2. Wire gauge size

3. Conductor length

4. Using a thicker wire

The correct answer is: Using a thicker wire

Using a thicker wire is least likely to contribute to electrical resistance because thicker wires, often referred to as having a larger gauge (or lower AWG number), actually reduce resistance. In electrical systems, resistance is influenced by several factors, including the properties of the conductor material, the length of the conductor, and its cross-sectional area (which is where wire gauge comes into play). When you use a thicker wire, the increased cross-sectional area allows more electrons to flow through it simultaneously, thus lowering the overall resistance encountered in the circuit. This is why thicker wires are preferred in applications that require high current, as they help to minimize power losses due to resistance. The other factors contribute to resistance in various ways. Poor wire connection quality can lead to higher resistance at the connection points due to increased contact resistance. A longer conductor length inherently increases resistance because there are more materials for current to navigate. A smaller wire gauge (thinner wire) increases resistance because it has less room for electron flow, which can lead to overheating and voltage drops. Therefore, the use of thicker wire is proactive in reducing resistance and enhancing the overall efficiency of an electrical system.