When the term voltage drop is used, it is generally in reference to:

• A. The difference in voltage between the source and the customer due to load
• B. The voltage difference between peak load and nominal load
• C. The voltage difference between the primary and the secondary
• D. The difference between the voltage at full load and no load

Answer: (A)

Voltage drop is the loss of voltage that occurs as power travels from the source through conductors and equipment to the load. When current flows, the line’s resistance and reactance use up part of the source voltage, so the voltage at the customer’s location is lower than at the source. The difference between the source voltage and the voltage at the customer end is the voltage drop, and it grows with higher current and greater impedance along the path. In practical terms, longer runs or smaller conductors have more impedance, so the drop is larger and utilities must ensure enough voltage remains at the far end.

Other descriptions don’t capture this path-to-load difference. A comparison between peak and nominal load focuses on loading levels rather than the actual voltage loss along the line. A primary-to-secondary difference describes a transformer’s turns ratio, not the drop along a distribution path. The full-load versus no-load difference is about voltage regulation, which is related but not the same as the voltage drop along the line under load.