Which factor directly influences voltage drop in a wire run?

Which factor directly influences voltage drop in a wire run?

• A. Distance in feet of the wire run
• B. System voltage
• C. Ambient temperature
• D. Number of conductors

Answer: (A)

Voltage drop along a wire is caused by the resistance the current encounters as it travels through the conductor. For a given material and gauge, resistance is directly proportional to the length of the path. So the longer the wire run, the more resistance the current meets, and the greater the voltage drop for the same current. That makes the distance in feet of the wire run the direct, primary factor influencing voltage drop. Ambient temperature can alter resistance slightly, and the number of conductors or the system voltage can affect overall behavior in some cases, but the length of the run most directly scales the path resistance and thus the voltage drop.

Voltage drop along a wire is caused by the resistance the current encounters as it travels through the conductor. For a given material and gauge, resistance is directly proportional to the length of the path. So the longer the wire run, the more resistance the current meets, and the greater the voltage drop for the same current. That makes the distance in feet of the wire run the direct, primary factor influencing voltage drop.

Ambient temperature can alter resistance slightly, and the number of conductors or the system voltage can affect overall behavior in some cases, but the length of the run most directly scales the path resistance and thus the voltage drop.