In designing wiring for voltage drop mitigation, which practice is employed?

• A. Using longer run lengths
• B. Using multiple feeds when appropriate
• C. Increasing resistance
• D. Reducing loads to zero

Answer: (B)

Voltage drop is the loss of voltage that occurs when current flows through the resistance of wiring. The amount of drop depends on how much current is going through a given length of conductor and how long that path is (V = I × R). To keep avionics and systems within their required voltage limits, engineers design runs to minimize this drop. Providing multiple feeds from the power source to different parts of a circuit is a common and effective method because each feed carries only a portion of the total current, and the individual run lengths are shorter. This reduces the current and resistance in each path, keeping the voltage at each device closer to nominal and improving reliability. Reducing loads to zero isn’t practical for normal operation, and making runs longer or increasing resistance would worsen the drop.